diff --git a/src/app/system_other.cpp b/src/app/system_other.cpp
index da81a6d5..9d9f76a1 100644
--- a/src/app/system_other.cpp
+++ b/src/app/system_other.cpp
@@ -33,7 +33,7 @@ long long int CSystemUtilsOther::GetTimeStampExactResolution()
     return 1000000ll;
 }
 
-long long int CSystemUtilsOther::TimeStampExactDiff(SystemTimeStamp* before, SystemTimeStamp* after) const
+long long int CSystemUtilsOther::TimeStampExactDiff(SystemTimeStamp* before, SystemTimeStamp* after)
 {
     return (after->sdlTicks - before->sdlTicks) * 1000000ll;
 }
diff --git a/src/app/system_other.h b/src/app/system_other.h
index b10a3265..7eccf3fa 100644
--- a/src/app/system_other.h
+++ b/src/app/system_other.h
@@ -40,10 +40,11 @@ struct SystemTimeStamp
 class CSystemUtilsOther : public CSystemUtils
 {
 public:
+    virtual void Init() {};
     virtual SystemDialogResult SystemDialog(SystemDialogType type, const std::string& title, const std::string& message) override;
 
     virtual void GetCurrentTimeStamp(SystemTimeStamp *stamp) override;
-    virtual long long GetTimeStampExactResolution() override;
+    virtual long long int GetTimeStampExactResolution() override;
     virtual long long TimeStampExactDiff(SystemTimeStamp *before, SystemTimeStamp *after) override;
 };