diff --git a/po/colobot.pot b/po/colobot.pot
index 266d13b1..7cbb92d7 100644
--- a/po/colobot.pot
+++ b/po/colobot.pot
@@ -1798,6 +1798,9 @@ msgstr ""
 msgid "Empty character constant"
 msgstr ""
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dividing by zero"
 msgstr ""
 
diff --git a/po/cs.po b/po/cs.po
index 7f1b50d4..b14eb434 100644
--- a/po/cs.po
+++ b/po/cs.po
@@ -489,6 +489,9 @@ msgstr "Dolů (\\key gdown;)"
 msgid "Drawer bot"
 msgstr "Tužkobot"
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dust\\Dust and dirt on bots and buildings"
 msgstr "Prach\\Prach a špína na robotech a budovách"
 
diff --git a/po/de.po b/po/de.po
index 61f72697..f031a049 100644
--- a/po/de.po
+++ b/po/de.po
@@ -490,6 +490,9 @@ msgstr "Sinkt (\\key gdown;)"
 msgid "Drawer bot"
 msgstr "Zeichner"
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dust\\Dust and dirt on bots and buildings"
 msgstr "Schmutz\\Schmutz auf Robotern und Bauten"
 
diff --git a/po/fr.po b/po/fr.po
index f0229e72..5c904b95 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -492,6 +492,9 @@ msgstr "Descend (\\key gdown;)"
 msgid "Drawer bot"
 msgstr "Robot dessinateur"
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dust\\Dust and dirt on bots and buildings"
 msgstr "Salissures\\Salissures des robots et bâtiments"
 
diff --git a/po/pl.po b/po/pl.po
index 5b9bab87..35be67e1 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -488,6 +488,9 @@ msgstr "Dół (\\key gdown;)"
 msgid "Drawer bot"
 msgstr "Robot rysownik"
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dust\\Dust and dirt on bots and buildings"
 msgstr "Kurz\\Kurz i bród na robotach i budynkach"
 
diff --git a/po/pt.po b/po/pt.po
index 53bdd07c..06bb43e3 100644
--- a/po/pt.po
+++ b/po/pt.po
@@ -487,6 +487,9 @@ msgstr "Baixo (\\key gdown;)"
 msgid "Drawer bot"
 msgstr "Robô cartoonista"
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dust\\Dust and dirt on bots and buildings"
 msgstr "Poeira\\Poeira e sujeira nos robôs e prédios"
 
diff --git a/po/ru.po b/po/ru.po
index df68516f..37852277 100644
--- a/po/ru.po
+++ b/po/ru.po
@@ -496,6 +496,9 @@ msgstr "Вниз (\\key gdown;)"
 msgid "Drawer bot"
 msgstr "Рисовальщик"
 
+msgid "Duplicate label in switch"
+msgstr ""
+
 msgid "Dust\\Dust and dirt on bots and buildings"
 msgstr "Пыль\\Пыль и грязь на ботах и зданиях"
 
diff --git a/src/CBot/CBotEnums.h b/src/CBot/CBotEnums.h
index 35775295..2f04707d 100644
--- a/src/CBot/CBotEnums.h
+++ b/src/CBot/CBotEnums.h
@@ -254,6 +254,7 @@ enum CBotError : int
     CBotErrHexRange      = 5053, //!< hex value out of range
     CBotErrUnicodeName   = 5054, //!< invalid universal character name
     CBotErrCharEmpty     = 5055, //!< empty character constant
+    CBotErrRedefCase     = 5056, //!< duplicate label in switch
 
     // Runtime errors
     CBotErrZeroDiv       = 6000, //!< division by zero
diff --git a/src/CBot/CBotInstr/CBotCase.cpp b/src/CBot/CBotInstr/CBotCase.cpp
index 15c8d4f7..2e0cc7f0 100644
--- a/src/CBot/CBotInstr/CBotCase.cpp
+++ b/src/CBot/CBotInstr/CBotCase.cpp
@@ -19,7 +19,7 @@
 
 #include "CBot/CBotInstr/CBotCase.h"
 
-#include "CBot/CBotInstr/CBotExprLitNum.h"
+#include "CBot/CBotInstr/CBotTwoOpExpr.h"
 
 #include "CBot/CBotStack.h"
 #include "CBot/CBotCStack.h"
@@ -30,69 +30,107 @@ namespace CBot
 ////////////////////////////////////////////////////////////////////////////////
 CBotCase::CBotCase()
 {
-    m_value = nullptr;
+    m_instr = nullptr;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 CBotCase::~CBotCase()
 {
-    delete m_value;
+    delete m_instr;
 }
 
-////////////////////////////////////////////////////////////////////////////////
-CBotInstr* CBotCase::Compile(CBotToken* &p, CBotCStack* pStack)
+CBotInstr* CBotCase::Compile(CBotToken* &p, CBotCStack* pStack, std::unordered_map<long, CBotInstr*>& labels)
 {
-    CBotCase*   inst = new CBotCase();          // creates the object
     CBotToken*  pp = p;                         // preserves at the ^ token (starting position)
 
-    inst->SetToken(p);
     if (!IsOfType(p, ID_CASE, ID_DEFAULT)) return nullptr;     // should never happen
+    pStack->SetStartError(pp->GetStart());
 
-    if ( pp->GetType() == ID_CASE )
+    long labelValue = 0;
+
+    if (pp->GetType() == ID_CASE)
     {
-        pp = p;
-        inst->m_value = CBot::CompileExprLitNum(p, pStack);
-        if (inst->m_value == nullptr )
+        CBotInstr* i = nullptr;
+        if (nullptr != (i = CBotTwoOpExpr::Compile(p, pStack, nullptr, true)))
         {
-            pStack->SetError( CBotErrBadNum, pp );
-            delete inst;
-            return nullptr;
+            if (pStack->GetType() <= CBotTypLong)
+            {
+                CBotStack* pile = CBotStack::AllocateStack();
+                while ( !i->Execute(pile) );
+                labelValue = pile->GetVar()->GetValLong();
+                pile->Delete();
+
+                if (labels.count(labelValue) > 0)
+                {
+                    pStack->SetError(CBotErrRedefCase, p->GetStart());
+                }
+            }
+            else
+                pStack->SetError(CBotErrBadNum, p->GetStart());
+            delete i;
         }
-    }
-    if ( !IsOfType( p, ID_DOTS ))
-    {
-        pStack->SetError( CBotErrNoDoubleDots, p->GetStart() );
-        delete inst;
-        return nullptr;
+        else
+            pStack->SetError(CBotErrBadNum, p->GetStart());
     }
 
-    return inst;
+    if (pStack->IsOk() && IsOfType(p, ID_DOTS))
+    {
+        CBotCase* newCase = new CBotCase();
+        newCase->SetToken(pp);
+        if (pp->GetType() == ID_CASE)
+            labels[labelValue] = newCase;
+        return newCase;
+    }
+
+    pStack->SetError(CBotErrNoDoubleDots, p->GetStart());
+    return nullptr;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 bool CBotCase::Execute(CBotStack* &pj)
 {
-    return true;                                // the "case" statement does nothing!
+    if (m_instr == nullptr) return true;
+    CBotStack* pile = pj->AddStack(this, CBotStack::BlockVisibilityType::BLOCK);
+
+    int state = pile->GetState();
+    CBotInstr* p = m_instr;
+    while (state-- > 0) p = p->GetNext();
+
+    while (p != nullptr)
+    {
+        if (!p->Execute(pile)) return false;
+        pile->IncState();
+        p = p->GetNext();
+    }
+
+    pile->Delete();
+    return pj->IsOk();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 void CBotCase::RestoreState(CBotStack* &pj, bool bMain)
 {
-}
+    if (!bMain) return;
 
-////////////////////////////////////////////////////////////////////////////////
-bool CBotCase::CompCase(CBotStack* &pile, int val)
-{
-    if (m_value == nullptr ) return true;         // "default" case
+    CBotStack* pile = pj->RestoreStack(this);
+    if (pile == nullptr) return;
 
-    while (!m_value->Execute(pile));            // puts the value on the correspondent stack (without interruption)
-    return (pile->GetVal() == val);             // compared with the given value
+    CBotInstr* p = m_instr;
+
+    int state = pile->GetState();
+    while (p != nullptr && state-- > 0)
+    {
+        p->RestoreState(pile, bMain);
+        p = p->GetNext();
+    }
+
+    if (p != nullptr) p->RestoreState(pile, bMain);
 }
 
 std::map<std::string, CBotInstr*> CBotCase::GetDebugLinks()
 {
     auto links = CBotInstr::GetDebugLinks();
-    links["m_value"] = m_value;
+    links["m_instr"] = m_instr;
     return links;
 }
 
diff --git a/src/CBot/CBotInstr/CBotCase.h b/src/CBot/CBotInstr/CBotCase.h
index e2863cde..ccd031e8 100644
--- a/src/CBot/CBotInstr/CBotCase.h
+++ b/src/CBot/CBotInstr/CBotCase.h
@@ -21,6 +21,8 @@
 
 #include "CBot/CBotInstr/CBotInstr.h"
 
+#include <unordered_map>
+
 namespace CBot
 {
 
@@ -42,7 +44,7 @@ public:
      * \param pStack
      * \return
      */
-    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack);
+    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack, std::unordered_map<long, CBotInstr*>& labels);
 
     /*!
      * \brief Execute Execution of instruction "case".
@@ -58,22 +60,15 @@ public:
      */
     void RestoreState(CBotStack* &pj, bool bMain) override;
 
-    /*!
-     * \brief CompCase Routine to find the entry point of "case" corresponding
-     * to the value seen.
-     * \param pj
-     * \param val
-     * \return
-     */
-    bool CompCase(CBotStack* &pj, int val) override;
-
 protected:
     virtual const std::string GetDebugName() override { return "CBotCase"; }
     virtual std::map<std::string, CBotInstr*> GetDebugLinks() override;
 
 private:
-    //! Value to compare.
-    CBotInstr* m_value;
+    //! List of instructions after case label
+    CBotInstr* m_instr;
+
+    friend class CBotSwitch;
 };
 
 } // namespace CBot
diff --git a/src/CBot/CBotInstr/CBotExprUnaire.cpp b/src/CBot/CBotInstr/CBotExprUnaire.cpp
index c39fd89e..d9a6c4d4 100644
--- a/src/CBot/CBotInstr/CBotExprUnaire.cpp
+++ b/src/CBot/CBotInstr/CBotExprUnaire.cpp
@@ -40,8 +40,7 @@ CBotExprUnaire::~CBotExprUnaire()
     delete m_expr;
 }
 
-////////////////////////////////////////////////////////////////////////////////
-CBotInstr* CBotExprUnaire::Compile(CBotToken* &p, CBotCStack* pStack, bool bLiteral)
+CBotInstr* CBotExprUnaire::Compile(CBotToken* &p, CBotCStack* pStack, bool bLiteral, bool bConstExpr)
 {
     int op = p->GetType();
     CBotToken*    pp = p;
@@ -52,8 +51,10 @@ CBotInstr* CBotExprUnaire::Compile(CBotToken* &p, CBotCStack* pStack, bool bLite
     CBotExprUnaire* inst = new CBotExprUnaire();
     inst->SetToken(pp);
 
-    if (!bLiteral) inst->m_expr = CBotParExpr::Compile(p, pStk);
-    else inst->m_expr = CBotParExpr::CompileLitExpr(p, pStk);
+    if (bConstExpr || !bLiteral)
+        inst->m_expr = CBotParExpr::Compile(p, pStk, bConstExpr);
+    else
+        inst->m_expr = CBotParExpr::CompileLitExpr(p, pStk);
 
     if (inst->m_expr != nullptr)
     {
diff --git a/src/CBot/CBotInstr/CBotExprUnaire.h b/src/CBot/CBotInstr/CBotExprUnaire.h
index 8a743a81..82d124a5 100644
--- a/src/CBot/CBotInstr/CBotExprUnaire.h
+++ b/src/CBot/CBotInstr/CBotExprUnaire.h
@@ -40,7 +40,7 @@ public:
      * \param bLiteral If true, compiles only literal expressions Ex: ~11, -4.0, !false, not true
      * \return The compiled instruction or nullptr
      */
-    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack, bool bLiteral = false);
+    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack, bool bLiteral = false, bool bConstExpr = false);
 
     /*!
      * \brief Execute
diff --git a/src/CBot/CBotInstr/CBotInstr.cpp b/src/CBot/CBotInstr/CBotInstr.cpp
index 04b13204..54d9cee9 100644
--- a/src/CBot/CBotInstr/CBotInstr.cpp
+++ b/src/CBot/CBotInstr/CBotInstr.cpp
@@ -317,13 +317,6 @@ void CBotInstr::RestoreStateVar(CBotStack* &pile, bool bMain)
     assert(0);            // dad do not know, see the girls
 }
 
-////////////////////////////////////////////////////////////////////////////////
-bool CBotInstr::CompCase(CBotStack* &pj, int val)
-{
-    return false;
-}
-
-////////////////////////////////////////////////////////////////////////////////
 CBotInstr* CBotInstr::CompileArray(CBotToken* &p, CBotCStack* pStack, CBotTypResult type, bool first)
 {
     if (IsOfType(p, ID_OPBRK))
diff --git a/src/CBot/CBotInstr/CBotInstr.h b/src/CBot/CBotInstr/CBotInstr.h
index 712b379d..2c4d5884 100644
--- a/src/CBot/CBotInstr/CBotInstr.h
+++ b/src/CBot/CBotInstr/CBotInstr.h
@@ -191,17 +191,6 @@ public:
     virtual void RestoreStateVar(CBotStack* &pile,
                                  bool bMain);
 
-    /**
-     * \brief CompCase This routine is defined only for the subclass CBotCase
-     * this allows to make the call on all instructions CompCase to see if it's
-     * a case to the desired value..
-     * \param pj
-     * \param val
-     * \return
-     */
-    virtual bool CompCase(CBotStack* &pj,
-                          int val);
-
     /**
      * \brief SetToken Set the token corresponding to the instruction.
      * \param p
diff --git a/src/CBot/CBotInstr/CBotParExpr.cpp b/src/CBot/CBotInstr/CBotParExpr.cpp
index fa455c27..9dd784bc 100644
--- a/src/CBot/CBotInstr/CBotParExpr.cpp
+++ b/src/CBot/CBotInstr/CBotParExpr.cpp
@@ -32,6 +32,7 @@
 #include "CBot/CBotInstr/CBotNew.h"
 #include "CBot/CBotInstr/CBotPostIncExpr.h"
 #include "CBot/CBotInstr/CBotPreIncExpr.h"
+#include "CBot/CBotInstr/CBotTwoOpExpr.h"
 
 #include "CBot/CBotVar/CBotVar.h"
 
@@ -40,13 +41,15 @@
 namespace CBot
 {
 
-////////////////////////////////////////////////////////////////////////////////
-CBotInstr* CBotParExpr::Compile(CBotToken* &p, CBotCStack* pStack)
+CBotInstr* CBotParExpr::Compile(CBotToken* &p, CBotCStack* pStack, bool bConstExpr)
 {
     CBotCStack* pStk = pStack->TokenStack();
 
     pStk->SetStartError(p->GetStart());
 
+    if (bConstExpr)
+        return CBotParExpr::CompileConstExpr(p, pStack);
+
     // is it an expression in parentheses?
     if (IsOfType(p, ID_OPENPAR))
     {
@@ -224,4 +227,55 @@ CBotInstr* CBotParExpr::CompileLitExpr(CBotToken* &p, CBotCStack* pStack)
     return pStack->Return(nullptr, pStk);
 }
 
+CBotInstr* CBotParExpr::CompileConstExpr(CBotToken* &p, CBotCStack* pStack)
+{
+    CBotCStack* pStk = pStack->TokenStack();
+
+    // is it an expression in parentheses?
+    if (IsOfType(p, ID_OPENPAR))
+    {
+        CBotInstr* inst = CBotTwoOpExpr::Compile(p, pStk, nullptr, true);
+
+        if (nullptr != inst)
+        {
+            if (IsOfType(p, ID_CLOSEPAR))
+            {
+                return pStack->Return(inst, pStk);
+            }
+            pStk->SetError(CBotErrClosePar, p->GetStart());
+        }
+        delete inst;
+        return pStack->Return(nullptr, pStk);
+    }
+
+    // is this a unary operation?
+    CBotInstr* inst = CBotExprUnaire::Compile(p, pStk, true, true);
+    if (inst != nullptr || !pStk->IsOk())
+        return pStack->Return(inst, pStk);
+
+    // is it a number or DefineNum?
+    if (p->GetType() == TokenTypNum ||
+        p->GetType() == TokenTypDef )
+    {
+        CBotInstr* inst = CBot::CompileExprLitNum(p, pStk);
+        return pStack->Return(inst, pStk);
+    }
+
+    // is this a character?
+    if (p->GetType() == TokenTypChar)
+    {
+        CBotInstr* inst = CBotExprLitChar::Compile(p, pStk);
+        return pStack->Return(inst, pStk);
+    }
+
+    // is it sizeof operator ?
+    inst = CBot::CompileSizeOf(p, pStk);
+    if (inst != nullptr || !pStk->IsOk())
+    {
+        return pStack->Return(inst, pStk);
+    }
+
+    return pStack->Return(nullptr, pStk);
+}
+
 } // namespace CBot
diff --git a/src/CBot/CBotInstr/CBotParExpr.h b/src/CBot/CBotInstr/CBotParExpr.h
index 235dab11..826b1cd1 100644
--- a/src/CBot/CBotInstr/CBotParExpr.h
+++ b/src/CBot/CBotInstr/CBotParExpr.h
@@ -52,7 +52,7 @@ public:
      * \param pStack
      * \return
      */
-    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack);
+    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack, bool bConstExpr = false);
 
     /*!
      * \brief Compile a literal expression ("string", number, true, false, null, nan, new)
@@ -62,6 +62,8 @@ public:
      */
     static CBotInstr* CompileLitExpr(CBotToken* &p, CBotCStack* pStack);
 
+    static CBotInstr* CompileConstExpr(CBotToken* &p, CBotCStack* pStack);
+
 private:
     CBotParExpr() = delete;
     CBotParExpr(const CBotParExpr&) = delete;
diff --git a/src/CBot/CBotInstr/CBotSwitch.cpp b/src/CBot/CBotInstr/CBotSwitch.cpp
index e8d1b24d..a889348b 100644
--- a/src/CBot/CBotInstr/CBotSwitch.cpp
+++ b/src/CBot/CBotInstr/CBotSwitch.cpp
@@ -57,7 +57,7 @@ CBotInstr* CBotSwitch::Compile(CBotToken* &p, CBotCStack* pStack)
     {
         if ( nullptr != (inst->m_value = CBotExpression::Compile(p, pStk )) )
         {
-            if ( pStk->GetType() < CBotTypLong )
+            if ( pStk->GetType() <= CBotTypLong )
             {
                 if ( IsOfType(p, ID_CLOSEPAR ) )
                 {
@@ -65,21 +65,35 @@ CBotInstr* CBotSwitch::Compile(CBotToken* &p, CBotCStack* pStack)
                     {
                         IncLvl();
 
+                        CBotCase* caseInst = nullptr;
+                        CBotCStack* pStk2 = nullptr;
                         while( !IsOfType( p, ID_CLBLK ) )
                         {
                             if ( p->GetType() == ID_CASE || p->GetType() == ID_DEFAULT)
                             {
-                                CBotCStack* pStk2 = pStk->TokenStack(p);    // un petit bout de pile svp
+                                delete pStk2;
+                                pStk2 = pStk->TokenStack(p, true);          // un petit bout de pile svp
 
-                                CBotInstr* i = CBotCase::Compile( p, pStk2 );
-                                if (i == nullptr)
+                                caseInst = static_cast<CBotCase*>(CBotCase::Compile(p, pStk2, inst->m_labels));
+                                if (caseInst == nullptr)
                                 {
                                     delete inst;
                                     return pStack->Return(nullptr, pStk2);
                                 }
-                                delete pStk2;
-                                if (inst->m_block == nullptr ) inst->m_block = i;
-                                else inst->m_block->AddNext(i);
+
+                                if (inst->m_block == nullptr ) inst->m_block = caseInst;
+                                else inst->m_block->AddNext(caseInst);
+
+                                if (ID_DEFAULT == caseInst->GetTokenType())
+                                {
+                                    if (inst->m_default != nullptr)
+                                    {
+                                        pStk->SetError(CBotErrRedefCase, caseInst->GetToken());
+                                        delete inst;
+                                        return pStack->Return(nullptr, pStk);
+                                    }
+                                    inst->m_default = caseInst;
+                                }
                                 continue;
                             }
 
@@ -90,13 +104,14 @@ CBotInstr* CBotSwitch::Compile(CBotToken* &p, CBotCStack* pStack)
                                 return pStack->Return(nullptr, pStk);
                             }
 
-                            CBotInstr* i = CBotBlock::CompileBlkOrInst( p, pStk, true );
-                            if ( !pStk->IsOk() )
+                            CBotInstr* i = CBotBlock::CompileBlkOrInst(p, pStk2);
+                            if ( !pStk2->IsOk() )
                             {
                                 delete inst;
-                                return pStack->Return(nullptr, pStk);
+                                return pStack->Return(nullptr, pStk2);
                             }
-                            inst->m_block->AddNext(i);
+                            if (caseInst->m_instr == nullptr ) caseInst->m_instr = i;
+                            else caseInst->m_instr->AddNext(i);
 
                             if ( p == nullptr )
                             {
@@ -133,40 +148,21 @@ CBotInstr* CBotSwitch::Compile(CBotToken* &p, CBotCStack* pStack)
 bool CBotSwitch :: Execute(CBotStack* &pj)
 {
     CBotStack* pile1 = pj->AddStack(this);      // adds an item to the stack
-//  if ( pile1 == EOX ) return true;
-
-    CBotInstr*  p = m_block;                    // first expression
 
     int     state = pile1->GetState();
     if (state == 0)
     {
         if ( !m_value->Execute(pile1) ) return false;
-        pile1->SetState(state = -1);
+        pile1->SetState(state = 1);
     }
 
     if ( pile1->IfStep() ) return false;
 
-    if ( state == -1 )
-    {
-        state = 0;
-        int val = pile1->GetVal();                      // result of the value
+    auto it = m_labels.find(pile1->GetVar()->GetValLong());
 
-        CBotStack* pile2 = pile1->AddStack();
-        while ( p != nullptr )                             // search for the corresponding case in a list
-        {
-            state++;
-            if ( p->CompCase( pile2, val ) ) break;     // found the case
-            p = p->GetNext();
-        }
-        pile2->Delete();
+    CBotInstr* p = (it != m_labels.end()) ? it->second : m_default;
 
-        if ( p == nullptr ) return pj->Return(pile1);      // completed if nothing
-
-        if ( !pile1->SetState(state) ) return false;
-    }
-
-    p = m_block;                                        // returns to the beginning
-    while (state-->0) p = p->GetNext();                 // advance in the list
+    while (--state > 0) p = p->GetNext();
 
     while( p != nullptr )
     {
@@ -185,8 +181,6 @@ void CBotSwitch :: RestoreState(CBotStack* &pj, bool bMain)
     CBotStack* pile1 = pj->RestoreStack(this);  // adds an item to the stack
     if ( pile1 == nullptr ) return;
 
-    CBotInstr*  p = m_block;                    // first expression
-
     int     state = pile1->GetState();
     if (state == 0)
     {
@@ -194,13 +188,11 @@ void CBotSwitch :: RestoreState(CBotStack* &pj, bool bMain)
         return;
     }
 
-    if ( state == -1 )
-    {
-        return;
-    }
+    auto it = m_labels.find(pile1->GetVar()->GetValLong());
 
-//  p = m_block;                                // returns to the beginning
-    while ( p != nullptr && state-- > 0 )
+    CBotInstr* p = (it != m_labels.end()) ? it->second : m_default;
+
+    while (p != nullptr && --state > 0)
     {
         p->RestoreState(pile1, false);
         p = p->GetNext();                       // advance in the list
diff --git a/src/CBot/CBotInstr/CBotSwitch.h b/src/CBot/CBotInstr/CBotSwitch.h
index ca6b2b20..0ebcddf0 100644
--- a/src/CBot/CBotInstr/CBotSwitch.h
+++ b/src/CBot/CBotInstr/CBotSwitch.h
@@ -21,6 +21,8 @@
 
 #include "CBot/CBotInstr/CBotInstr.h"
 
+#include <unordered_map>
+
 namespace CBot
 {
 
@@ -64,8 +66,12 @@ protected:
 private:
     //! Value to seek
     CBotInstr* m_value;
-    //! Instructions
-    CBotInstr* m_block;
+    //! List of case instructions
+    CBotInstr* m_block = nullptr;
+    //! Pointer to default label
+    CBotInstr* m_default = nullptr;
+    //! Map of case labels
+    std::unordered_map<long, CBotInstr*> m_labels;
 };
 
 } // namespace CBot
diff --git a/src/CBot/CBotInstr/CBotTwoOpExpr.cpp b/src/CBot/CBotInstr/CBotTwoOpExpr.cpp
index ab8b0da9..c1b2d278 100644
--- a/src/CBot/CBotInstr/CBotTwoOpExpr.cpp
+++ b/src/CBot/CBotInstr/CBotTwoOpExpr.cpp
@@ -133,8 +133,7 @@ static bool TypeOk(int type, int test)
     }
 }
 
-////////////////////////////////////////////////////////////////////////////////
-CBotInstr* CBotTwoOpExpr::Compile(CBotToken* &p, CBotCStack* pStack, int* pOperations)
+CBotInstr* CBotTwoOpExpr::Compile(CBotToken* &p, CBotCStack* pStack, int* pOperations, bool bConstExpr)
 {
     int typeMask;
 
@@ -146,8 +145,8 @@ CBotInstr* CBotTwoOpExpr::Compile(CBotToken* &p, CBotCStack* pStack, int* pOpera
 
     // search the intructions that may be suitable to the left of the operation
     CBotInstr*  left = (*pOp == 0) ?
-                        CBotParExpr::Compile( p, pStk ) :       // expression (...) left
-                        CBotTwoOpExpr::Compile( p, pStk, pOp ); // expression A * B left
+                        CBotParExpr::Compile(p, pStk, bConstExpr) :       // expression (...) left
+                        CBotTwoOpExpr::Compile(p, pStk, pOp, bConstExpr); // expression A * B left
 
     if (left == nullptr) return pStack->Return(nullptr, pStk);        // if error,  transmit
 
@@ -158,7 +157,7 @@ CBotInstr* CBotTwoOpExpr::Compile(CBotToken* &p, CBotCStack* pStack, int* pOpera
         CBotTypResult    type1, type2;
         type1 = pStk->GetTypResult();                           // what kind of the first operand?
 
-        if (typeOp == ID_LOGIC)       // special case provided for: ? op1: op2;
+        if (!bConstExpr && typeOp == ID_LOGIC) // special case provided for: ? op1: op2;
         {
             if ( !type1.Eq(CBotTypBoolean) )
             {
@@ -207,7 +206,7 @@ CBotInstr* CBotTwoOpExpr::Compile(CBotToken* &p, CBotCStack* pStack, int* pOpera
 
         // looking statements that may be suitable for right
 
-        if ( nullptr != (inst->m_rightop = CBotTwoOpExpr::Compile( p, pStk, pOp )) )
+        if ( nullptr != (inst->m_rightop = CBotTwoOpExpr::Compile(p, pStk, pOp, bConstExpr)) )
                                                                 // expression (...) right
         {
             // there is an second operand acceptable
@@ -264,7 +263,7 @@ CBotInstr* CBotTwoOpExpr::Compile(CBotToken* &p, CBotCStack* pStack, int* pOpera
                     type1 = TypeRes;
 
                     p = p->GetNext();                                       // advance after
-                    i->m_rightop = CBotTwoOpExpr::Compile( p, pStk, pOp );
+                    i->m_rightop = CBotTwoOpExpr::Compile(p, pStk, pOp, bConstExpr);
                     type2 = pStk->GetTypResult();
 
                     if ( !TypeCompatible (type1, type2, typeOp) )       // the results are compatible
diff --git a/src/CBot/CBotInstr/CBotTwoOpExpr.h b/src/CBot/CBotInstr/CBotTwoOpExpr.h
index c1110e13..baf70a14 100644
--- a/src/CBot/CBotInstr/CBotTwoOpExpr.h
+++ b/src/CBot/CBotInstr/CBotTwoOpExpr.h
@@ -65,7 +65,7 @@ public:
      * \param pOperations
      * \return
      */
-    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack, int* pOperations = nullptr);
+    static CBotInstr* Compile(CBotToken* &p, CBotCStack* pStack, int* pOperations = nullptr, bool bConstExpr = false);
 
     /*!
      * \brief Execute Performes the operation on two operands.
diff --git a/src/common/restext.cpp b/src/common/restext.cpp
index 065f6c92..a79f3f55 100644
--- a/src/common/restext.cpp
+++ b/src/common/restext.cpp
@@ -743,6 +743,7 @@ void InitializeRestext()
     stringsCbot[CBot::CBotErrHexRange]      = TR("Hex value out of range");
     stringsCbot[CBot::CBotErrUnicodeName]   = TR("Invalid universal character name");
     stringsCbot[CBot::CBotErrCharEmpty]     = TR("Empty character constant");
+    stringsCbot[CBot::CBotErrRedefCase]     = TR("Duplicate label in switch");
 
     stringsCbot[CBot::CBotErrZeroDiv]       = TR("Dividing by zero");
     stringsCbot[CBot::CBotErrNotInit]       = TR("Variable not initialized");
diff --git a/test/unit/CBot/CBot_test.cpp b/test/unit/CBot/CBot_test.cpp
index 4c60b8fa..78009ffc 100644
--- a/test/unit/CBot/CBot_test.cpp
+++ b/test/unit/CBot/CBot_test.cpp
@@ -640,6 +640,92 @@ TEST_F(CBotUT, BinaryLiterals)
     );
 }
 
+TEST_F(CBotUT, TestSwitchCase)
+{
+    ExecuteTest(
+        "extern void Test_Switch_Case() {\n"
+        "    int n = 0, c = 0;\n"
+        "    for (int i = -9; i < 11; ++i) {\n"
+        "        switch (i) {\n"
+        "            case -9: n = -9; ++c; break;\n"
+        "            case -8: n = -8; ++c; break;\n"
+        "            case -7: n = -7; ++c; break;\n"
+        "            case -6: n = -6; ++c; break;\n"
+        "            case -5: n = -5; ++c; break;\n"
+        "            case -4: n = -4; ++c; break;\n"
+        "            case -3: n = -3; ++c; break;\n"
+        "            case -2: n = -2; ++c; break;\n"
+        "            case -1: n = -1; ++c; break;\n"
+        "            case 0: n = 0; ++c; break;\n"
+        "            case 1: n = 1; ++c; break;\n"
+        "            case 2: n = 2; ++c; break;\n"
+        "            case 3: n = 3; ++c; break;\n"
+        "            case 4: n = 4; ++c; break;\n"
+        "            case 5: n = 5; ++c; break;\n"
+        "            case 6: n = 6; ++c; break;\n"
+        "            case 7: n = 7; ++c; break;\n"
+        "            case 8: n = 8; ++c; break;\n"
+        "            case 9: n = 9; ++c; break;\n"
+        "            default: n = 10; ++c; break;\n"
+        "        }\n"
+        "        ASSERT(n == i);\n"
+        "    }\n"
+        "    ASSERT(n == 10);\n"
+        "    ASSERT(c == 20);\n"
+        "}\n"
+        "extern void Test_Case_With_Math() {\n"
+        "    int n = 0, c = 0;\n"
+        "    for (int i = -9; i < 11; ++i) {\n"
+        "        switch (i * 10) {\n"
+        "            case -9*10: n = -90; ++c; break;\n"
+        "            case -8*10: n = -80; ++c; break;\n"
+        "            case -7*10: n = -70; ++c; break;\n"
+        "            case -6*10: n = -60; ++c; break;\n"
+        "            case -5*10: n = -50; ++c; break;\n"
+        "            case -4*10: n = -40; ++c; break;\n"
+        "            case -3*10: n = -30; ++c; break;\n"
+        "            case -2*10: n = -20; ++c; break;\n"
+        "            case -1*10: n = -10; ++c; break;\n"
+        "            case 0*10: n = 0; ++c; break;\n"
+        "            case 1*10: n = 10; ++c; break;\n"
+        "            case 2*10: n = 20; ++c; break;\n"
+        "            case 3*10: n = 30; ++c; break;\n"
+        "            case 4*10: n = 40; ++c; break;\n"
+        "            case 5*10: n = 50; ++c; break;\n"
+        "            case 6*10: n = 60; ++c; break;\n"
+        "            case 7*10: n = 70; ++c; break;\n"
+        "            case 8*10: n = 80; ++c; break;\n"
+        "            case 9*10: n = 90; ++c; break;\n"
+        "            default: n = 100; ++c; break;\n"
+        "        }\n"
+        "        ASSERT(n == i * 10);\n"
+        "    }\n"
+        "    ASSERT(n == 100);\n"
+        "    ASSERT(c == 20);\n"
+        "}\n"
+    );
+
+    ExecuteTest(
+        "extern void Duplicate_Case() {\n"
+        "    switch(0) {\n"
+        "        case 1000:\n"
+        "        case 10*100:\n"
+        "    }\n"
+        "}\n",
+        CBotErrRedefCase
+    );
+
+    ExecuteTest(
+        "extern void Duplicate_Default() {\n"
+        "    switch(0) {\n"
+        "        default:\n"
+        "        default:\n"
+        "    }\n"
+        "}\n",
+        CBotErrRedefCase
+    );
+}
+
 TEST_F(CBotUT, ToString)
 {
     ExecuteTest(