diff --git a/engines/grim/gfx_opengl.cpp b/engines/grim/gfx_opengl.cpp
index 7ae5dcdacaf..57274383a67 100644
--- a/engines/grim/gfx_opengl.cpp
+++ b/engines/grim/gfx_opengl.cpp
@@ -439,7 +439,7 @@ void GfxOpenGL::drawEMIModelFace(const EMIModel* model, const EMIMeshFace* face)
 	glEnable(GL_TEXTURE_2D);
 
 	glBegin(GL_TRIANGLES);
-	for (int j = 0; j < face->_faceLength * 3; j++) {
+	for (uint j = 0; j < face->_faceLength * 3; j++) {
 
 		int index = indices[j];
 		if (face->_hasTexture) {
@@ -1145,8 +1145,8 @@ void GfxOpenGL::drawMovieFrame(int offsetX, int offsetY) {
 	glDepthMask(GL_FALSE);
 	glEnable(GL_SCISSOR_TEST);
 
-	offsetX *= _scaleW;
-	offsetY *= _scaleH;
+	offsetX = (int)(offsetX * _scaleW);
+	offsetY = (int)(offsetY * _scaleH);
 
 	glScissor(offsetX, _screenHeight - (offsetY + _smushHeight), _smushWidth, _smushHeight);
 
diff --git a/engines/grim/gfx_tinygl.cpp b/engines/grim/gfx_tinygl.cpp
index f6a910d9e3e..ba8d266aeb6 100644
--- a/engines/grim/gfx_tinygl.cpp
+++ b/engines/grim/gfx_tinygl.cpp
@@ -560,7 +560,7 @@ void GfxTinyGL::drawEMIModelFace(const EMIModel* model, const EMIMeshFace* face)
 	else
 		tglDisable(TGL_TEXTURE_2D);
 	tglBegin(TGL_TRIANGLES);
-	for (int j = 0; j < face->_faceLength * 3; j++) {
+	for (uint j = 0; j < face->_faceLength * 3; j++) {
 
 		int index = indices[j];
 		if (face->_hasTexture) {
@@ -1089,7 +1089,7 @@ void GfxTinyGL::dimRegion(int x, int y, int w, int h, float level) {
 		for (int lx = x; lx < x + w; lx++) {
 			uint8 r, g, b;
 			_zb->pbuf.getRGBAt(ly * _gameWidth + lx, r, g, b);
-			uint32 color = ((r + g + b) / 3) * level;
+			uint32 color = (uint32)(((r + g + b) / 3) * level);
 			_zb->pbuf.setPixelAt(ly * _gameWidth + lx, color, color, color);
 		}
 	}