diff --git a/common/2d/bitmap.cpp b/common/2d/bitmap.cpp
index 6416cdb30..36cc57e08 100644
--- a/common/2d/bitmap.cpp
+++ b/common/2d/bitmap.cpp
@@ -132,7 +132,7 @@ void gr_init_sub_bitmap (grs_bitmap &bm, grs_bitmap &bmParent, uint16_t x, uint1
 	bm.gltexture = bmParent.gltexture;
 #endif
 	bm.bm_parent = &bmParent;
-	bm.bm_data = &bmParent.bm_data[(unsigned int)((y*bmParent.bm_rowsize)+x)];
+	bm.bm_data = &bmParent.bm_data[static_cast<uint32_t>((y*bmParent.bm_rowsize)+x)];
 }
 
 void decode_data(ubyte *data, uint_fast32_t num_pixels, array<color_t, 256> &colormap, array<unsigned, 256> &count)