diff --git a/src/kits/interface/Bitmap.cpp b/src/kits/interface/Bitmap.cpp
index ca484ae152..e5bdfe2bcb 100644
--- a/src/kits/interface/Bitmap.cpp
+++ b/src/kits/interface/Bitmap.cpp
@@ -665,7 +665,11 @@ BBitmap::SetBits(const void* data, int32 length, int32 offset,
 	int32 inBPR = -1;
 	// tweaks to mimic R5 behavior
 	if (error == B_OK) {
-		if (colorSpace == B_CMAP8 && fColorSpace != B_CMAP8) {
+		if (colorSpace == B_RGB32) {
+			// B_RGB32 means actually unpadded B_RGB24_BIG
+			colorSpace = B_RGB24_BIG;
+			inBPR = width * 3;
+		} else if (colorSpace == B_CMAP8 && fColorSpace != B_CMAP8) {
 			// If in color space is B_CMAP8, but the bitmap's is another one,
 			// ignore source data row padding.
 			inBPR = width;