diff --git a/reactos/win32ss/gdi/eng/bitblt.c b/reactos/win32ss/gdi/eng/bitblt.c
index 8b6dd0009d2..83bc508470d 100644
--- a/reactos/win32ss/gdi/eng/bitblt.c
+++ b/reactos/win32ss/gdi/eng/bitblt.c
@@ -460,6 +460,19 @@ EngBitBlt(
         clippingType = pco->iDComplexity;
     }
 
+    /* Check if we need a mask but have no mask surface */
+    if (UsesMask && (psoMask == NULL))
+    {
+        /* Check if the BRUSHOBJ can provide the mask */
+        psoMask = BRUSHOBJ_psoMask(pbo);
+        if (psoMask == NULL)
+        {
+            /* We have no mask, assume the mask is all foreground */
+            rop4 &= (rop4 & 0xFF) || ((rop4 & 0xFF) << 8);
+            UsesMask = FALSE;
+        }
+    }
+
     if (UsesMask)
     {
         BltRectFunc = BltMask;
diff --git a/reactos/win32ss/gdi/eng/bitblt_new.c b/reactos/win32ss/gdi/eng/bitblt_new.c
index b5fdd1bf473..56bfade89f4 100644
--- a/reactos/win32ss/gdi/eng/bitblt_new.c
+++ b/reactos/win32ss/gdi/eng/bitblt_new.c
@@ -210,7 +210,7 @@ EngBitBlt(
     if (ROP4_USES_PATTERN(rop4))
     {
         /* Must have a brush */
-        ASSERT(pbo); // FIXME: test this!
+        NT_ASSERT(pbo); // FIXME: test this!
 
         /* Copy the solid color */
         bltdata.ulSolidColor = pbo->iSolidColor;
@@ -253,12 +253,23 @@ EngBitBlt(
     /* Check if the ROP uses a mask */
     if (ROP4_USES_MASK(rop4))
     {
-        /* Must have a mask surface and point */
-        ASSERT(psoMask);
-        ASSERT(pptlMask);
-
         //__debugbreak();
 
+        /* Check if we don't have a mask surface */
+        if (psoMask == NULL)
+        {
+            /* Must have a brush */
+            NT_ASSERT(pbo); // FIXME: test this!
+
+            /* Check if the BRUSHOBJ can provide the mask */
+            psoMask = BRUSHOBJ_psoMask(pbo);
+            if (psoMask == NULL)
+            {
+                /* We have no mask, assume the mask is all foreground */
+                rop4 = (rop4 & 0xFF) || ((rop4 & 0xFF) << 8);
+            }
+        }
+
         /* Set the mask format info */
         bltdata.siMsk.iFormat = psoMask->iBitmapFormat;
         bltdata.siMsk.pvScan0 = psoMask->pvScan0;
diff --git a/reactos/win32ss/gdi/eng/paint.c b/reactos/win32ss/gdi/eng/paint.c
index 95d334dc8f1..97874489cfe 100644
--- a/reactos/win32ss/gdi/eng/paint.c
+++ b/reactos/win32ss/gdi/eng/paint.c
@@ -63,9 +63,8 @@ EngPaint(
     /* Convert the MIX, consisting of 2 ROP2 codes into a ROP4 */
     rop4 = MIX_TO_ROP4(mix);
 
-    /* Sanity checks */
+    /* Sanity check */
     NT_ASSERT(!ROP4_USES_SOURCE(rop4));
-    NT_ASSERT(!ROP4_USES_MASK(rop4));
 
     /* Forward the call to Eng/DrvBitBlt */
     return IntEngBitBlt(pso,