diff --git a/src/mon.c b/src/mon.c
index 5088005ed..bee0e0040 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -3964,6 +3964,10 @@ pickvampshape(struct monst* mon)
         mndx = (!rn2(4) && !uppercase_only) ? PM_FOG_CLOUD : PM_VAMPIRE_BAT;
         break;
     }
+
+    if (g.mvitals[mndx].mvflags & G_GENOD)
+        return mon->cham;
+
     return mndx;
 }