diff --git a/proto/lib.go b/proto/lib.go
index 083f104..1d7ed89 100644
--- a/proto/lib.go
+++ b/proto/lib.go
@@ -145,16 +145,16 @@
 			}
 			data, err := proto.Marshal(test)
 			if err != nil {
-				log.Exit("marshaling error:", err)
+				log.Fatal("marshaling error: ", err)
 			}
 			newTest := new(example.Test)
 			err = proto.Unmarshal(data, newTest)
 			if err != nil {
-				log.Exit("unmarshaling error:", err)
+				log.Fatal("unmarshaling error: ", err)
 			}
 			// Now test and newTest contain the same data.
 			if proto.GetString(test.Label) != proto.GetString(newTest.Label) {
-				log.Exit("data mismatch %q %q", proto.GetString(test.Label), proto.GetString(newTest.Label))
+				log.Fatalf("data mismatch %q != %q", proto.GetString(test.Label), proto.GetString(newTest.Label))
 			}
 			// etc.
 		}