diff --git a/src/render/WaterLevel.h b/src/render/WaterLevel.h
index cf3537ae..b797f251 100644
--- a/src/render/WaterLevel.h
+++ b/src/render/WaterLevel.h
@@ -79,7 +79,7 @@ class CWaterLevel
 	static int16       nGeomUsed;
 
 public:
-	static void    Initialise(Const char *pWaterDat);
+	static void    Initialise(Const char *pWaterDat); // out of class in III PC and later because of SecuROM
 	static void    Shutdown();
 	static void    CreateWavyAtomic();
 	static void    DestroyWavyAtomic();
diff --git a/src/vehicles/Heli.cpp b/src/vehicles/Heli.cpp
index 7008818b..56d6a8eb 100644
--- a/src/vehicles/Heli.cpp
+++ b/src/vehicles/Heli.cpp
@@ -785,7 +785,7 @@ CHeli::InitHelis(void)
 }
 
 CHeli*
-GenerateHeli(bool catalina)
+CHeli::GenerateHeli(bool catalina)
 {
 	CHeli *heli;
 	CVector heliPos;
diff --git a/src/vehicles/Heli.h b/src/vehicles/Heli.h
index cf3f791f..5fef799b 100644
--- a/src/vehicles/Heli.h
+++ b/src/vehicles/Heli.h
@@ -81,12 +81,13 @@ public:
 	CObject *SpawnFlyingComponent(int32 component);
 
 	static void InitHelis(void);
+	static CHeli *GenerateHeli(bool catalina); // out of class in III PC and later because of SecuROM
 	static void UpdateHelis(void);
 	static void SpecialHeliPreRender(void);
 	static bool TestRocketCollision(CVector *coors);
 	static bool TestBulletCollision(CVector *line0, CVector *line1, CVector *bulletPos, int32 damage);
 
-	static void StartCatalinaFlyBy(void);
+	static void StartCatalinaFlyBy(void); // out of class in III PC and later because of SecuROM
 	static void RemoveCatalinaHeli(void);
 	static CHeli *FindPointerToCatalinasHeli(void);
 	static void CatalinaTakeOff(void);