diff --git a/src/pkg/testing/benchmark.go b/src/pkg/testing/benchmark.go
index d82007e2ced..ad938027d3e 100644
--- a/src/pkg/testing/benchmark.go
+++ b/src/pkg/testing/benchmark.go
@@ -175,7 +175,7 @@ func RunBenchmarks(matchString func(pat, str string) (bool, os.Error), benchmark
 	for _, Benchmark := range benchmarks {
 		matched, err := matchString(*matchBenchmarks, Benchmark.Name)
 		if err != nil {
-			println("invalid regexp for -benchmarks:", err)
+			println("invalid regexp for -benchmarks:", err.String())
 			os.Exit(1)
 		}
 		if !matched {
diff --git a/src/pkg/testing/testing.go b/src/pkg/testing/testing.go
index ae6d0346461..0e04935ce44 100644
--- a/src/pkg/testing/testing.go
+++ b/src/pkg/testing/testing.go
@@ -144,7 +144,7 @@ func Main(matchString func(pat, str string) (bool, os.Error), tests []InternalTe
 	for i := 0; i < len(tests); i++ {
 		matched, err := matchString(*match, tests[i].Name)
 		if err != nil {
-			println("invalid regexp for -match:", err)
+			println("invalid regexp for -match:", err.String())
 			os.Exit(1)
 		}
 		if !matched {