diff --git a/src/potion.c b/src/potion.c
index 9f5d0c722..9a4731e2c 100644
--- a/src/potion.c
+++ b/src/potion.c
@@ -2834,7 +2834,7 @@ split_mon(
             disp.botl = TRUE;
             You("multiply%s!", reason);
         }
-    } else {
+    } else if (mon->mhpmax > 1) {
         mtmp2 = clone_mon(mon, 0, 0);
         if (mtmp2) {
             mtmp2->mhpmax = mon->mhpmax / 2;