diff --git a/reactos/subsys/win32k/eng/bitblt.c b/reactos/subsys/win32k/eng/bitblt.c
index 91ba8835bb1..c582ebf678d 100644
--- a/reactos/subsys/win32k/eng/bitblt.c
+++ b/reactos/subsys/win32k/eng/bitblt.c
@@ -128,6 +128,14 @@ EngBitBlt(SURFOBJ *Dest,
     }
   }
 
+  /* The code currently assumes there will be a source bitmap. This is not true when, for example, using this function to
+   * paint a brush pattern on the destination. */
+  if(!Source)
+  {
+    DbgPrint("EngBitBlt: A source is currently required, even though not all operations require one (FIXME)\n");
+    return FALSE;
+  }
+
   // * The source bitmap is not managed by the GDI and we didn't already obtain it using EngCopyBits from the device
   if(Source->iType != STYPE_BITMAP && SourceGDI->CopyBits == NULL)
   {
diff --git a/reactos/subsys/win32k/objects/fillshap.c b/reactos/subsys/win32k/objects/fillshap.c
index a7f10517dc0..0e06ee26445 100644
--- a/reactos/subsys/win32k/objects/fillshap.c
+++ b/reactos/subsys/win32k/objects/fillshap.c
@@ -134,26 +134,30 @@ W32kRectangle(HDC  hDC,
                     RectBounds, // Bounding rectangle
                     dc->w.ROPmode); // MIX */
 
+    // FIXME: BrushObj is obtained above; decide which one is correct
     BrushObj = (BRUSHOBJ*) GDIOBJ_LockObj(dc->w.hBrush, GO_BRUSH_MAGIC);
-    assert(BrushObj);
-    if (BrushObj->logbrush.lbStyle != BS_NULL)
-      {	
-	DestRect.left = LeftRect + 1;
-	DestRect.right = RightRect - 1;
-	DestRect.top = TopRect + 1;
-	DestRect.bottom = BottomRect - 1;
-	ret = EngBitBlt(SurfObj, 
-			NULL,
-			NULL,
-			NULL,
-			NULL,
-			&DestRect,
-			NULL,
-			NULL,
-			BrushObj,
-			NULL,
-			PATCOPY);
-      }
+
+    if (BrushObj)
+    {
+      if (BrushObj->logbrush.lbStyle != BS_NULL)
+        {	
+          DestRect.left = LeftRect + 1;
+          DestRect.right = RightRect - 1;
+          DestRect.top = TopRect + 1;
+          DestRect.bottom = BottomRect - 1;
+          ret = EngBitBlt(SurfObj, 
+                          NULL,
+                          NULL,
+                          NULL,
+                          NULL,
+                          &DestRect,
+                          NULL,
+                          NULL,
+                          BrushObj,
+                          NULL,
+                          PATCOPY);
+        }
+    }
     GDIOBJ_UnlockObj( dc->w.hBrush, GO_PEN_MAGIC );	
   }