diff --git a/programs/winemenubuilder/winemenubuilder.c b/programs/winemenubuilder/winemenubuilder.c
index 4675369..eac4cd6 100644
--- a/programs/winemenubuilder/winemenubuilder.c
+++ b/programs/winemenubuilder/winemenubuilder.c
@@ -599,6 +599,7 @@ static int populate_module_icons(HMODULE hModule, GRPICONDIR *grpIconDir, ICONDI
 {
     int i;
     int validEntries = 0;
+    static const BYTE png_header[] = { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A };
 
     for (i = 0; i < grpIconDir->idCount; i++)
     {
@@ -610,19 +611,32 @@ static int populate_module_icons(HMODULE hModule, GRPICONDIR *grpIconDir, ICONDI
             if ((hResData = LoadResource(hModule, hResInfo)))
             {
                 BITMAPINFO *pIcon;
+                DWORD availableBytes = ((IMAGE_RESOURCE_DATA_ENTRY *)hResInfo)->Size;
+                DWORD iconBytes = grpIconDir->idEntries[i].dwBytesInRes;
+                if (iconBytes > availableBytes)
+                {
+                    WINE_ERR("Broken GRPICONENTRY tries to use %d bytes when only %d available, clipping\n", iconBytes, availableBytes);
+                    iconBytes = availableBytes;
+                }
                 if ((pIcon = LockResource(hResData)))
                 {
+                    BOOL isPNG = iconBytes >= sizeof(png_header) && memcmp(pIcon, png_header, sizeof(png_header)) == 0;
+                    if (isPNG)
+                    {
+                        WINE_FIXME("PNG icon not supported\n");
+                        continue;
+                    }
                     iconDirEntries[validEntries].bWidth = grpIconDir->idEntries[i].bWidth;
                     iconDirEntries[validEntries].bHeight = grpIconDir->idEntries[i].bHeight;
                     iconDirEntries[validEntries].bColorCount = grpIconDir->idEntries[i].bColorCount;
                     iconDirEntries[validEntries].bReserved = grpIconDir->idEntries[i].bReserved;
                     iconDirEntries[validEntries].wPlanes = grpIconDir->idEntries[i].wPlanes;
                     iconDirEntries[validEntries].wBitCount = grpIconDir->idEntries[i].wBitCount;
-                    iconDirEntries[validEntries].dwBytesInRes = grpIconDir->idEntries[i].dwBytesInRes;
+                    iconDirEntries[validEntries].dwBytesInRes = iconBytes;
                     iconDirEntries[validEntries].dwImageOffset = *iconOffset;
                     validEntries++;
-                    memcpy(&icons[*iconOffset], pIcon, grpIconDir->idEntries[i].dwBytesInRes);
-                    *iconOffset += grpIconDir->idEntries[i].dwBytesInRes;
+                    memcpy(&icons[*iconOffset], pIcon, iconBytes);
+                    *iconOffset += iconBytes;
                 }
                 FreeResource(hResData);
             }