diff --git a/engines/prince/graphics.cpp b/engines/prince/graphics.cpp
index b86628009f33..c993cc890567 100644
--- a/engines/prince/graphics.cpp
+++ b/engines/prince/graphics.cpp
@@ -46,6 +46,8 @@ GraphicsMan::GraphicsMan(PrinceEngine *vm)
 GraphicsMan::~GraphicsMan() {
 	_frontScreen->free();
 	delete _frontScreen;
+	_screenForInventory->free();
+	delete _screenForInventory;
 	delete[] _shadowTable70;
 	delete[] _shadowTable50;
 }
diff --git a/engines/prince/prince.cpp b/engines/prince/prince.cpp
index 83a471a6ed28..0df1f778c659 100644
--- a/engines/prince/prince.cpp
+++ b/engines/prince/prince.cpp
@@ -140,6 +140,8 @@ PrinceEngine::~PrinceEngine() {
 	}
 	_maskList.clear();
 
+	freeDrawNodes();
+
 	clearBackAnimList();
 
 	for (uint i = 0; i < _allInvList.size(); i++) {
@@ -404,6 +406,8 @@ bool PrinceEngine::loadLocation(uint16 locationNr) {
 		_mobList[i]._visible = _script->getMobVisible(i);
 	}
 
+	freeDrawNodes();
+
 	clearBackAnimList();
 	_script->installBackAnims(_backAnimList, _room->_backAnim);
 
@@ -855,8 +859,10 @@ int PrinceEngine::checkMob(Graphics::Surface *screen, Common::Array<Mob> &mobLis
 						int phase = backAnim._showFrame;
 						int phaseFrameIndex = backAnim._animData->getPhaseFrameIndex(phase);
 						Graphics::Surface *backAnimSurface = backAnim._animData->getFrame(phaseFrameIndex);
-						byte *pixel = (byte *)backAnimSurface->getBasePtr(mousePosCamera.x - backAnim._currX, mousePosCamera.y - backAnim._currY);
-						if (*pixel != 255) {
+						byte pixel = *(byte *)backAnimSurface->getBasePtr(mousePosCamera.x - backAnim._currX, mousePosCamera.y - backAnim._currY);
+						backAnimSurface->free();
+						delete backAnimSurface;
+						if (pixel != 255) {
 							break;
 						}
 					}
@@ -923,13 +929,11 @@ int PrinceEngine::checkMob(Graphics::Surface *screen, Common::Array<Mob> &mobLis
 	return -1;
 }
 
-void PrinceEngine::printAt(uint32 slot, uint8 color, const char *s, uint16 x, uint16 y) {
+void PrinceEngine::printAt(uint32 slot, uint8 color, char *s, uint16 x, uint16 y) {
 
 	debugC(1, DebugChannel::kEngine, "PrinceEngine::printAt slot %d, color %d, x %02d, y %02d, str %s", slot, color, x, y, s);
 
-	char *destStr = (char *)malloc(strlen(s));
-	strcpy(destStr, s);
-	char *strPointer = destStr;
+	char *strPointer = s;
 
 	if (getLanguage() == Common::DE_DEU) {
 		while (*strPointer) {
@@ -961,7 +965,7 @@ void PrinceEngine::printAt(uint32 slot, uint8 color, const char *s, uint16 x, ui
 	}
 
 	Text &text = _textSlots[slot];
-	text._str = destStr;
+	text._str = s;
 	text._x = x;
 	text._y = y;
 	text._color = color;
@@ -1140,6 +1144,9 @@ void PrinceEngine::showSprite(Graphics::Surface *spriteSurface, int destX, int d
 		newDrawNode.freeSurfaceSMemory = freeSurfaceMemory;
 		newDrawNode.drawFunction = &_graph->drawTransparentDrawNode;
 		_drawNodeList.push_back(newDrawNode);
+	} else if (freeSurfaceMemory) {
+		spriteSurface->free();
+		delete spriteSurface;
 	}
 }
 
@@ -1159,6 +1166,9 @@ void PrinceEngine::showSpriteShadow(Graphics::Surface *shadowSurface, int destX,
 		newDrawNode.freeSurfaceSMemory = freeSurfaceMemory;
 		newDrawNode.drawFunction = &_graph->drawAsShadowDrawNode;
 		_drawNodeList.push_back(newDrawNode);
+	} else if (freeSurfaceMemory) {
+		shadowSurface->free();
+		delete shadowSurface;
 	}
 }
 
@@ -1906,7 +1916,7 @@ void PrinceEngine::inventoryLeftMouseButton() {
 		int invObjExamEvent = _script->scanMobEvents(_invMobList[_selectedMob]._mask, _script->_scriptInfo.invObjExam);
 		if (invObjExamEvent == -1) {
 			// do_standard
-			printAt(0, 216, _invMobList[_selectedMob]._examText.c_str(), kNormalWidth / 2, _invExamY);
+			printAt(0, 216, (char *)_invMobList[_selectedMob]._examText.c_str(), kNormalWidth / 2, _invExamY);
 			_interpreter->setCurrentString(_invMobList[_selectedMob]._mask + 70000);
 			setVoice(0, 28, 1);
 			playSample(28, 0);
diff --git a/engines/prince/prince.h b/engines/prince/prince.h
index e1da3ba41bb7..0d3bae26f6e1 100644
--- a/engines/prince/prince.h
+++ b/engines/prince/prince.h
@@ -250,7 +250,7 @@ class PrinceEngine : public Engine {
 	virtual GUI::Debugger *getDebugger();
 
 	void changeCursor(uint16 curId);
-	void printAt(uint32 slot, uint8 color, const char *s, uint16 x, uint16 y);
+	void printAt(uint32 slot, uint8 color, char *s, uint16 x, uint16 y);
 	int calcText(const char *s);
 
 	static const uint8 MAXTEXTS = 32;
diff --git a/engines/prince/script.cpp b/engines/prince/script.cpp
index 910c8617067b..d5284034e2d0 100644
--- a/engines/prince/script.cpp
+++ b/engines/prince/script.cpp
@@ -462,7 +462,7 @@ void Interpreter::debugInterpreter(const char *s, ...) {
 	Common::String str = Common::String::format("@0x%08X: ", _lastInstruction);
 	str += Common::String::format("op %04d: ", _lastOpcode);
 	//debugC(10, DebugChannel::kScript, "PrinceEngine::Script %s %s", str.c_str(), buf);
-	if (_mode == "fg") {
+	if (!strcmp(_mode, "fg")) {
 		debug(10, "PrinceEngine::Script %s %s", str.c_str(), buf);
 	}
 	//debug("Prince::Script frame %08ld mode %s %s %s", _vm->_frameNr, _mode, str.c_str(), buf);
@@ -834,7 +834,7 @@ void Interpreter::O_SETSTRING() {
 	_currentString = offset;
 
 	if (offset >= 80000) {
-		_string = (const byte *)_vm->_variaTxt->getString(offset - 80000);
+		_string = (byte *)_vm->_variaTxt->getString(offset - 80000);
 		debugInterpreter("GetVaria %s", _string);
 	}
 	else if (offset < 2000) {
@@ -911,7 +911,7 @@ void Interpreter::O_XORFLAG() {
 void Interpreter::O_GETMOBTEXT() {
 	uint16 mob = readScriptFlagValue();
 	_currentString = _vm->_locationNr * 100 + mob + 60001;
-	_string = (const byte *)_vm->_mobList[mob]._examText.c_str();
+	_string = (byte *)_vm->_mobList[mob]._examText.c_str();
 
 	debugInterpreter("O_GETMOBTEXT mob %d", mob);
 }
@@ -1239,7 +1239,7 @@ void Interpreter::O_PRINTAT() {
 
 	uint8 color = _flags->getFlagValue(Flags::KOLOR);
 
-	_vm->printAt(slot, color, (const char *)_string, fr1, fr2);
+	_vm->printAt(slot, color, (char *)_string, fr1, fr2);
 
 	increaseString();
 }
diff --git a/engines/prince/script.h b/engines/prince/script.h
index 36fff1ceb995..d550ebc9bf82 100644
--- a/engines/prince/script.h
+++ b/engines/prince/script.h
@@ -209,7 +209,7 @@ class Interpreter {
 	//uint8 _savedStacktop;
 	uint32 _waitFlag;
 
-	const byte *_string;
+	byte *_string;
 	uint32 _currentString;
 	const char *_mode;
 
diff --git a/engines/prince/variatxt.cpp b/engines/prince/variatxt.cpp
index fdca8c2c775b..56fbd2911a84 100644
--- a/engines/prince/variatxt.cpp
+++ b/engines/prince/variatxt.cpp
@@ -42,12 +42,12 @@ bool VariaTxt::loadFromStream(Common::SeekableReadStream &stream) {
 	return true;
 }
 
-const char *VariaTxt::getString(uint32 stringId) {
+char *VariaTxt::getString(uint32 stringId) {
 	uint32 stringOffset = READ_LE_UINT32(_data + stringId * 4);
 	if (stringOffset > _dataSize) {
 		assert(false);
 	}
-	return (const char *)_data + stringOffset;
+	return (char *)_data + stringOffset;
 }
 
 }
diff --git a/engines/prince/variatxt.h b/engines/prince/variatxt.h
index 2a7a5fda9c56..b7fc7e3ac54a 100644
--- a/engines/prince/variatxt.h
+++ b/engines/prince/variatxt.h
@@ -32,7 +32,7 @@ class VariaTxt {
 
 	bool loadFromStream(Common::SeekableReadStream &stream);
 
-	const char *getString(uint32 stringId);
+	char *getString(uint32 stringId);
 
 private:
 	uint32 _dataSize;