diff --git a/logging/mock.go b/logging/mock.go
index fe1a42d..e5456d7 100644
--- a/logging/mock.go
+++ b/logging/mock.go
@@ -61,7 +61,9 @@ func (m writerMap) CheckWrittenAtLevel(t *testing.T, lv LogLevel, exp string) {
 	// 2011/10/22 10:22:57 log_test.go:<line no>: <level> <log message>
 	if len(w.written) <= 33 {
 		t.Errorf("Not enough bytes logged at level %s:", LogString(lv))
-		t.Errorf("\tgot: %s", string(w.written))
+		t.Errorf("exp: %s\n\tgot: %s", exp, string(w.written))
+		// Check nothing was written to a different log level here, too.
+		m.CheckNothingWritten(t)
 		return
 	}
 	s := string(w.written[32:])
@@ -73,7 +75,7 @@ func (m writerMap) CheckWrittenAtLevel(t *testing.T, lv LogLevel, exp string) {
 	exp = LogString(lv) + " " + exp
 	if s != exp {
 		t.Errorf("Log message at level %s differed.", LogString(lv))
-		t.Errorf("\texp: %s\n\tgot: %s", exp, s)
+		t.Errorf("exp: %s\n\tgot: %s", exp, s)
 	}
 	w.reset()
 	// Calling checkNothingWritten here both tests that w.reset() works