diff --git a/doc/fixes34.3 b/doc/fixes34.3
index 8d65e1f21..c9f0e157d 100644
--- a/doc/fixes34.3
+++ b/doc/fixes34.3
@@ -83,6 +83,7 @@ allow Conflict-resistant monsters to respond to conflict attacks rather than
 prefer herbivorous stone-to-flesh message when hero is a vegitarian
 try even harder to avoid incorrect map display while changing levels
 no "freaked" message by exploding black light, unless you really are
+sleeping monster could respond to attacks by other monsters
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/src/mhitm.c b/src/mhitm.c
index d3d941b66..3562365eb 100644
--- a/src/mhitm.c
+++ b/src/mhitm.c
@@ -203,7 +203,7 @@ mattackm(magr, mdef)
     struct permonst *pa, *pd;
 
     if (!magr || !mdef) return(MM_MISS);		/* mike@genat */
-    if (!magr->mcanmove) return(MM_MISS);		/* riv05!a3 */
+    if (!magr->mcanmove || magr->msleeping) return(MM_MISS);
     pa = magr->data;  pd = mdef->data;
 
     /* Grid bugs cannot attack at an angle. */