diff --git a/sys/src/ape/lib/ap/mips/lock.c b/sys/src/ape/lib/ap/mips/lock.c
index 866d074e9..7adb31a48 100644
--- a/sys/src/ape/lib/ap/mips/lock.c
+++ b/sys/src/ape/lib/ap/mips/lock.c
@@ -127,7 +127,8 @@ retry:
 			}
 		}
 		return 0;
-	}	
+	}
+	return -1;	/* not reached */
 }
 
 void
@@ -167,5 +168,6 @@ retry:
 			}
 		}
 		return 1;
-	}	
+	}
+	return -1;	/* not reached */
 }