diff --git a/src/libespeak-ng/compiledict.c b/src/libespeak-ng/compiledict.c
index e9540e19..21b04ecf 100644
--- a/src/libespeak-ng/compiledict.c
+++ b/src/libespeak-ng/compiledict.c
@@ -1141,8 +1141,8 @@ static char *compile_rule(char *input)
 		len += (strlen(rule_post)+1);
 	}
 	output[len++] = 0;
-	prule = (char *)malloc(len);
-	memcpy(prule, output, len);
+	if ((prule = (char *)malloc(len)) != NULL)
+		memcpy(prule, output, len);
 	return prule;
 }