diff --git a/doc/fixes34.1 b/doc/fixes34.1
index 497c3eaa6..f7c48803a 100644
--- a/doc/fixes34.1
+++ b/doc/fixes34.1
@@ -125,6 +125,7 @@ prevent getting stuck in infinite loop when using wizard mode #levelchange
 naming an already wielded elven dagger "Sting" activates warning against orcs
 naming either of the wielded weapons unintentionally ends two-weapon combat
 Various nemesis monsters must resist stoning so their death messages make sense
+don't call DEBUG impossible in rn2 when a level 0 monster tries to cast a spell
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/src/mcastu.c b/src/mcastu.c
index e1f2bffff..595b6a13f 100644
--- a/src/mcastu.c
+++ b/src/mcastu.c
@@ -181,7 +181,7 @@ castmu(mtmp, mattk, thinks_it_foundyou, foundyou)
 	 * attacking casts spells only a small portion of the time that an
 	 * attacking monster does.
 	 */
-	if (mattk->adtyp == AD_SPEL || mattk->adtyp == AD_CLRC) {
+	if ((mattk->adtyp == AD_SPEL || mattk->adtyp == AD_CLRC) && ml) {
 	    int cnt = 40;
 
 	    do {