diff --git a/src/3rdparty/squirrel/squirrel/sqdebug.cpp b/src/3rdparty/squirrel/squirrel/sqdebug.cpp
--- a/src/3rdparty/squirrel/squirrel/sqdebug.cpp
+++ b/src/3rdparty/squirrel/squirrel/sqdebug.cpp
@@ -91,7 +91,7 @@ SQString *SQVM::PrintObjVal(const SQObje
 	}
 }
 
-void SQVM::Raise_IdxError(SQObject &o)
+void SQVM::Raise_IdxError(const SQObject &o)
 {
 	SQObjectPtr oval = PrintObjVal(o);
 	Raise_Error(_SC("the index '%.50s' does not exist"), _stringval(oval));
diff --git a/src/3rdparty/squirrel/squirrel/sqvm.cpp b/src/3rdparty/squirrel/squirrel/sqvm.cpp
--- a/src/3rdparty/squirrel/squirrel/sqvm.cpp
+++ b/src/3rdparty/squirrel/squirrel/sqvm.cpp
@@ -459,7 +459,7 @@ bool SQVM::DerefInc(SQInteger op,SQObjec
 #define sarg1 (*(const_cast<SQInt32 *>(&_i_._arg1)))
 #define arg2 (_i_._arg2)
 #define arg3 (_i_._arg3)
-#define sarg3 ((SQInteger)*((signed char *)&_i_._arg3))
+#define sarg3 ((SQInteger)*((const signed char *)&_i_._arg3))
 
 SQRESULT SQVM::Suspend()
 {
@@ -742,7 +742,7 @@ exception_restore:
 				continue;
 			case _OP_LOAD: TARGET = ci->_literals[arg1]; continue;
 			case _OP_LOADINT: TARGET = (SQInteger)arg1; continue;
-			case _OP_LOADFLOAT: TARGET = *((SQFloat *)&arg1); continue;
+			case _OP_LOADFLOAT: TARGET = *((const SQFloat *)&arg1); continue;
 			case _OP_DLOAD: TARGET = ci->_literals[arg1]; STK(arg2) = ci->_literals[arg3];continue;
 			case _OP_TAILCALL:
 				temp_reg = STK(arg1);
@@ -1434,7 +1434,7 @@ bool SQVM::DeleteSlot(const SQObjectPtr 
 					_table(self)->Remove(key);
 				}
 				else {
-					Raise_IdxError((SQObject &)key);
+					Raise_IdxError((const SQObject &)key);
 					return false;
 				}
 			}
diff --git a/src/3rdparty/squirrel/squirrel/sqvm.h b/src/3rdparty/squirrel/squirrel/sqvm.h
--- a/src/3rdparty/squirrel/squirrel/sqvm.h
+++ b/src/3rdparty/squirrel/squirrel/sqvm.h
@@ -84,7 +84,7 @@ public:
 
 	void Raise_Error(const SQChar *s, ...);
 	void Raise_Error(SQObjectPtr &desc);
-	void Raise_IdxError(SQObject &o);
+	void Raise_IdxError(const SQObject &o);
 	void Raise_CompareError(const SQObject &o1, const SQObject &o2);
 	void Raise_ParamTypeError(SQInteger nparam,SQInteger typemask,SQInteger type);
 
diff --git a/src/blitter/32bpp_anim.cpp b/src/blitter/32bpp_anim.cpp
--- a/src/blitter/32bpp_anim.cpp
+++ b/src/blitter/32bpp_anim.cpp
@@ -44,7 +44,7 @@ inline void Blitter_32bppAnim::Draw(cons
 		const Colour *src_px_ln = (const Colour *)((const byte *)src_px + *(const uint32 *)src_px);
 		src_px++;
 
-		const uint8 *src_n_ln = src_n + *(uint32 *)src_n;
+		const uint8 *src_n_ln = src_n + *(const uint32 *)src_n;
 		src_n += 4;
 
 		uint32 *dst_end = dst + bp->skip_left;
@@ -296,7 +296,7 @@ void Blitter_32bppAnim::CopyFromBuffer(v
 	assert(!_screen_disable_anim);
 	assert(video >= _screen.dst_ptr && video <= (uint32 *)_screen.dst_ptr + _screen.width + _screen.height * _screen.pitch);
 	uint32 *dst = (uint32 *)video;
-	uint32 *usrc = (uint32 *)src;
+	const uint32 *usrc = (const uint32 *)src;
 	uint8 *anim_line = ((uint32 *)video - (uint32 *)_screen.dst_ptr) + this->anim_buf;
 
 	for (; height > 0; height--) {
@@ -309,7 +309,7 @@ void Blitter_32bppAnim::CopyFromBuffer(v
 		dst += _screen.pitch;
 		/* Copy back the anim-buffer */
 		memcpy(anim_line, usrc, width * sizeof(uint8));
-		usrc = (uint32 *)((uint8 *)usrc + width);
+		usrc = (const uint32 *)((const uint8 *)usrc + width);
 		anim_line += this->anim_buf_width;
 
 		/* Okay, it is *very* likely that the image we stored is using
@@ -336,12 +336,12 @@ void Blitter_32bppAnim::CopyToBuffer(con
 	assert(!_screen_disable_anim);
 	assert(video >= _screen.dst_ptr && video <= (uint32 *)_screen.dst_ptr + _screen.width + _screen.height * _screen.pitch);
 	uint32 *udst = (uint32 *)dst;
-	uint32 *src = (uint32 *)video;
-	uint8 *anim_line;
+	const uint32 *src = (const uint32 *)video;
+	const uint8 *anim_line;
 
 	if (this->anim_buf == NULL) return;
 
-	anim_line = ((uint32 *)video - (uint32 *)_screen.dst_ptr) + this->anim_buf;
+	anim_line = ((const uint32 *)video - (uint32 *)_screen.dst_ptr) + this->anim_buf;
 
 	for (; height > 0; height--) {
 		memcpy(udst, src, width * sizeof(uint32));
diff --git a/src/blitter/32bpp_base.cpp b/src/blitter/32bpp_base.cpp
--- a/src/blitter/32bpp_base.cpp
+++ b/src/blitter/32bpp_base.cpp
@@ -12,7 +12,7 @@
 #include "../stdafx.h"
 #include "32bpp_base.hpp"
 
-void *Blitter_32bppBase::MoveTo(const void *video, int x, int y)
+void *Blitter_32bppBase::MoveTo(void *video, int x, int y)
 {
 	return (uint32 *)video + x + y * _screen.pitch;
 }
@@ -39,7 +39,7 @@ void Blitter_32bppBase::DrawRect(void *v
 void Blitter_32bppBase::CopyFromBuffer(void *video, const void *src, int width, int height)
 {
 	uint32 *dst = (uint32 *)video;
-	uint32 *usrc = (uint32 *)src;
+	const uint32 *usrc = (const uint32 *)src;
 
 	for (; height > 0; height--) {
 		memcpy(dst, usrc, width * sizeof(uint32));
@@ -51,7 +51,7 @@ void Blitter_32bppBase::CopyFromBuffer(v
 void Blitter_32bppBase::CopyToBuffer(const void *video, void *dst, int width, int height)
 {
 	uint32 *udst = (uint32 *)dst;
-	uint32 *src = (uint32 *)video;
+	const uint32 *src = (const uint32 *)video;
 
 	for (; height > 0; height--) {
 		memcpy(udst, src, width * sizeof(uint32));
@@ -63,7 +63,7 @@ void Blitter_32bppBase::CopyToBuffer(con
 void Blitter_32bppBase::CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch)
 {
 	uint32 *udst = (uint32 *)dst;
-	uint32 *src = (uint32 *)video;
+	const uint32 *src = (const uint32 *)video;
 
 	for (; height > 0; height--) {
 		memcpy(udst, src, width * sizeof(uint32));
diff --git a/src/blitter/32bpp_base.hpp b/src/blitter/32bpp_base.hpp
--- a/src/blitter/32bpp_base.hpp
+++ b/src/blitter/32bpp_base.hpp
@@ -20,7 +20,7 @@
 class Blitter_32bppBase : public Blitter {
 public:
 	/* virtual */ uint8 GetScreenDepth() { return 32; }
-	/* virtual */ void *MoveTo(const void *video, int x, int y);
+	/* virtual */ void *MoveTo(void *video, int x, int y);
 	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
 	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
diff --git a/src/blitter/32bpp_optimized.cpp b/src/blitter/32bpp_optimized.cpp
--- a/src/blitter/32bpp_optimized.cpp
+++ b/src/blitter/32bpp_optimized.cpp
@@ -40,7 +40,7 @@ inline void Blitter_32bppOptimized::Draw
 	/* skip upper lines in src_px and src_n */
 	for (uint i = bp->skip_top; i != 0; i--) {
 		src_px = (const Colour *)((const byte *)src_px + *(const uint32 *)src_px);
-		src_n += *(uint32 *)src_n;
+		src_n += *(const uint32 *)src_n;
 	}
 
 	/* skip lines in dst */
@@ -58,7 +58,7 @@ inline void Blitter_32bppOptimized::Draw
 		src_px++;
 
 		/* next src_n line begins here */
-		const uint8 *src_n_ln = src_n + *(uint32 *)src_n;
+		const uint8 *src_n_ln = src_n + *(const uint32 *)src_n;
 		src_n += 4;
 
 		/* we will end this line when we reach this point */
diff --git a/src/blitter/8bpp_base.cpp b/src/blitter/8bpp_base.cpp
--- a/src/blitter/8bpp_base.cpp
+++ b/src/blitter/8bpp_base.cpp
@@ -23,7 +23,7 @@ void Blitter_8bppBase::DrawColourMapping
 	} while (--height);
 }
 
-void *Blitter_8bppBase::MoveTo(const void *video, int x, int y)
+void *Blitter_8bppBase::MoveTo(void *video, int x, int y)
 {
 	return (uint8 *)video + x + y * _screen.pitch;
 }
@@ -44,7 +44,7 @@ void Blitter_8bppBase::DrawRect(void *vi
 void Blitter_8bppBase::CopyFromBuffer(void *video, const void *src, int width, int height)
 {
 	uint8 *dst = (uint8 *)video;
-	uint8 *usrc = (uint8 *)src;
+	const uint8 *usrc = (const uint8 *)src;
 
 	for (; height > 0; height--) {
 		memcpy(dst, usrc, width * sizeof(uint8));
@@ -56,7 +56,7 @@ void Blitter_8bppBase::CopyFromBuffer(vo
 void Blitter_8bppBase::CopyToBuffer(const void *video, void *dst, int width, int height)
 {
 	uint8 *udst = (uint8 *)dst;
-	uint8 *src = (uint8 *)video;
+	const uint8 *src = (const uint8 *)video;
 
 	for (; height > 0; height--) {
 		memcpy(udst, src, width * sizeof(uint8));
@@ -68,7 +68,7 @@ void Blitter_8bppBase::CopyToBuffer(cons
 void Blitter_8bppBase::CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch)
 {
 	uint8 *udst = (uint8 *)dst;
-	uint8 *src = (uint8 *)video;
+	const uint8 *src = (const uint8 *)video;
 
 	for (; height > 0; height--) {
 		memcpy(udst, src, width * sizeof(uint8));
diff --git a/src/blitter/8bpp_base.hpp b/src/blitter/8bpp_base.hpp
--- a/src/blitter/8bpp_base.hpp
+++ b/src/blitter/8bpp_base.hpp
@@ -19,7 +19,7 @@ class Blitter_8bppBase : public Blitter 
 public:
 	/* virtual */ uint8 GetScreenDepth() { return 8; }
 	/* virtual */ void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal);
-	/* virtual */ void *MoveTo(const void *video, int x, int y);
+	/* virtual */ void *MoveTo(void *video, int x, int y);
 	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
 	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
diff --git a/src/blitter/base.hpp b/src/blitter/base.hpp
--- a/src/blitter/base.hpp
+++ b/src/blitter/base.hpp
@@ -87,7 +87,7 @@ public:
 	 * @param y How much you want to scroll to the bottom.
 	 * @return A new destination pointer moved the the requested place.
 	 */
-	virtual void *MoveTo(const void *video, int x, int y) = 0;
+	virtual void *MoveTo(void *video, int x, int y) = 0;
 
 	/**
 	 * Draw a pixel with a given colour on the video-buffer.
diff --git a/src/blitter/null.hpp b/src/blitter/null.hpp
--- a/src/blitter/null.hpp
+++ b/src/blitter/null.hpp
@@ -21,7 +21,7 @@ public:
 	/* virtual */ void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom) {};
 	/* virtual */ void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal) {};
 	/* virtual */ Sprite *Encode(SpriteLoader::Sprite *sprite, AllocatorProc *allocator);
-	/* virtual */ void *MoveTo(const void *video, int x, int y) { return NULL; };
+	/* virtual */ void *MoveTo(void *video, int x, int y) { return NULL; };
 	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour) {};
 	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour) {};
 	/* virtual */ void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width) {};