diff --git a/src/CBot/CBotProgram.h b/src/CBot/CBotProgram.h
index 2b477bda..9f5cdc00 100644
--- a/src/CBot/CBotProgram.h
+++ b/src/CBot/CBotProgram.h
@@ -143,7 +143,7 @@ public:
      * \param[out] code Error code
      * \param[out] start Starting position in the code string of this error
      * \param[out] end Ending position in the code string of this error
-     * \return false if no error has occured
+     * \return false if no error has occurred
      */
     bool GetError(CBotError& code, int& start, int& end);
 
@@ -153,7 +153,7 @@ public:
      * \param[out] start Starting position in the code string of this error
      * \param[out] end Ending position in the code string of this error
      * \param[out] pProg Program that caused the error (TODO: This always returns "this"... what?)
-     * \return false if no error has occured
+     * \return false if no error has occurred
      */
     bool GetError(CBotError& code, int& start, int& end, CBotProgram*& pProg);
 
diff --git a/src/CBot/CBotStack.h b/src/CBot/CBotStack.h
index 1d7c7884..6cd8e567 100644
--- a/src/CBot/CBotStack.h
+++ b/src/CBot/CBotStack.h
@@ -105,7 +105,7 @@ public:
 
     /**
      * \brief Check if there was an error
-     * \return false if an error occured
+     * \return false if an error occurred
      * \see GetError()
      */
     bool IsOk()
diff --git a/src/app/signal_handlers.cpp b/src/app/signal_handlers.cpp
index 1f29dc61..87dbb4ac 100644
--- a/src/app/signal_handlers.cpp
+++ b/src/app/signal_handlers.cpp
@@ -124,7 +124,7 @@ void CSignalHandlers::ReportError(const std::string& errorMessage)
     }
 
     std::stringstream msg;
-    msg << "Unhandled exception occured!" << std::endl;
+    msg << "Unhandled exception occurred!" << std::endl;
     msg << "==============================" << std::endl;
     msg << errorMessage << std::endl;
     msg << "==============================" << std::endl;
@@ -162,7 +162,7 @@ void CSignalHandlers::ReportError(const std::string& errorMessage)
 
     std::cerr << std::endl << msg.str() << std::endl;
 
-    m_systemUtils->SystemDialog(SDT_ERROR, "Unhandled exception occured!", msg.str());
+    m_systemUtils->SystemDialog(SDT_ERROR, "Unhandled exception occurred!", msg.str());
 
     if (canSave && !triedSaving)
     {
diff --git a/src/graphics/opengl/gl21device.cpp b/src/graphics/opengl/gl21device.cpp
index 6f7051e3..f5fb7741 100644
--- a/src/graphics/opengl/gl21device.cpp
+++ b/src/graphics/opengl/gl21device.cpp
@@ -174,7 +174,7 @@ bool CGL21Device::Create()
 
     if (!InitializeGLEW())
     {
-        m_errorMessage = "An error occured while initializing GLEW.";
+        m_errorMessage = "An error occurred while initializing GLEW.";
         return false;
     }
 
diff --git a/src/graphics/opengl/gl33device.cpp b/src/graphics/opengl/gl33device.cpp
index d02ff77a..c0c1e124 100644
--- a/src/graphics/opengl/gl33device.cpp
+++ b/src/graphics/opengl/gl33device.cpp
@@ -173,7 +173,7 @@ bool CGL33Device::Create()
 
     if (!InitializeGLEW())
     {
-        m_errorMessage = "An error occured while initializing GLEW.";
+        m_errorMessage = "An error occurred while initializing GLEW.";
         return false;
     }
 
diff --git a/src/graphics/opengl/gldevice.cpp b/src/graphics/opengl/gldevice.cpp
index 95a96fea..423520d6 100644
--- a/src/graphics/opengl/gldevice.cpp
+++ b/src/graphics/opengl/gldevice.cpp
@@ -169,7 +169,7 @@ bool CGLDevice::Create()
 
     if (!InitializeGLEW())
     {
-        m_errorMessage = "An error occured while initializing GLEW.";
+        m_errorMessage = "An error occurred while initializing GLEW.";
         return false;
     }
 
diff --git a/src/graphics/opengl/glutil.cpp b/src/graphics/opengl/glutil.cpp
index 95c1f24f..04ad80a9 100644
--- a/src/graphics/opengl/glutil.cpp
+++ b/src/graphics/opengl/glutil.cpp
@@ -480,8 +480,8 @@ GLint LoadShader(GLint type, const char* filename)
         auto message = MakeUniqueArray<GLchar>(len + 1);
         glGetShaderInfoLog(shader, len + 1, nullptr, message.get());
 
-        GetLogger()->Error("Shader compilation error occured!\n%s\n", message.get());
-        lastShaderError = std::string("Shader compilation error occured!\n\n") + std::string(message.get());
+        GetLogger()->Error("Shader compilation error occurred!\n%s\n", message.get());
+        lastShaderError = std::string("Shader compilation error occurred!\n\n") + std::string(message.get());
 
         glDeleteShader(shader);
         return 0;
@@ -513,8 +513,8 @@ GLint LinkProgram(int count, GLint shaders[])
         auto message = MakeUniqueArray<GLchar>(len + 1);
         glGetProgramInfoLog(program, len + 1, nullptr, message.get());
 
-        GetLogger()->Error("Shader program linking error occured!\n%s\n", message.get());
-        lastShaderError = std::string("Shader program linking error occured!\n\n") + std::string(message.get());
+        GetLogger()->Error("Shader program linking error occurred!\n%s\n", message.get());
+        lastShaderError = std::string("Shader program linking error occurred!\n\n") + std::string(message.get());
 
         glDeleteProgram(program);
 
diff --git a/src/level/robotmain.cpp b/src/level/robotmain.cpp
index 9506fcaf..d7f71be2 100644
--- a/src/level/robotmain.cpp
+++ b/src/level/robotmain.cpp
@@ -563,7 +563,7 @@ void CRobotMain::ChangePhase(Phase phase)
         }
         catch (const std::runtime_error& e)
         {
-            LevelLoadingError("An error occured while trying to load a level", e);
+            LevelLoadingError("An error occurred while trying to load a level", e);
         }
     }
 
@@ -606,7 +606,7 @@ void CRobotMain::ChangePhase(Phase phase)
             }
             catch (const std::runtime_error& e)
             {
-                LevelLoadingError("An error occured while trying to load win scene", e);
+                LevelLoadingError("An error occurred while trying to load win scene", e);
             }
         }
     }
@@ -636,7 +636,7 @@ void CRobotMain::ChangePhase(Phase phase)
             }
             catch (const std::runtime_error& e)
             {
-                LevelLoadingError("An error occured while trying to load lost scene", e);
+                LevelLoadingError("An error occurred while trying to load lost scene", e);
             }
         }
     }
@@ -2781,7 +2781,7 @@ void CRobotMain::ScenePerso()
     }
     catch (const std::runtime_error& e)
     {
-        LevelLoadingError("An error occured while trying to load apperance scene", e, PHASE_PLAYER_SELECT);
+        LevelLoadingError("An error occurred while trying to load apperance scene", e, PHASE_PLAYER_SELECT);
     }
 
     m_engine->SetDrawWorld(false);  // does not draw anything on the interface
@@ -4986,7 +4986,7 @@ void CRobotMain::ResetCreate()
     }
     catch (const std::runtime_error& e)
     {
-        LevelLoadingError("An error occured while trying to reset scene", e);
+        LevelLoadingError("An error occurred while trying to reset scene", e);
     }
 }