diff --git a/mm/madvise.c b/mm/madvise.c
index 9113579..ce3a422 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -386,7 +386,7 @@
 	}
 }
 
-static int
+static bool
 madvise_behavior_valid(int behavior)
 {
 	switch (behavior) {
@@ -408,10 +408,10 @@
 #endif
 	case MADV_DONTDUMP:
 	case MADV_DODUMP:
-		return 1;
+		return true;
 
 	default:
-		return 0;
+		return false;
 	}
 }