diff --git a/src/cmd/go/testdata/script/test_regexps.txt b/src/cmd/go/testdata/script/test_regexps.txt
index 020b8dd579..39dedbf06f 100644
--- a/src/cmd/go/testdata/script/test_regexps.txt
+++ b/src/cmd/go/testdata/script/test_regexps.txt
@@ -2,31 +2,38 @@ go test -cpu=1 -run=X/Y -bench=X/Y -count=2 -v testregexp
 
 # Test the following:
 
-#	TestX is run, twice
+# TestX is run, twice
 stdout -count=2 '^=== RUN   TestX$'
 stdout -count=2 '^    TestX: x_test.go:6: LOG: X running$'
 
-#	TestX/Y is run, twice
+# TestX/Y is run, twice
 stdout -count=2 '^=== RUN   TestX/Y$'
 stdout -count=2 '^    TestX/Y: x_test.go:8: LOG: Y running$'
 
-#	TestXX is run, twice
+# TestXX is run, twice
 stdout -count=2 '^=== RUN   TestXX$'
 stdout -count=2 '^    TestXX: z_test.go:10: LOG: XX running'
 
-#	TestZ is not run
+# TestZ is not run
 ! stdout '^=== RUN   TestZ$'
 
-#	BenchmarkX is run but only with N=1, once
-stdout -count=1 '^    BenchmarkX: x_test.go:13: LOG: X running N=1$'
-! stdout '^    BenchmarkX: x_test.go:13: LOG: X running N=10$'
+# BenchmarkX is run with N=1 once, only to discover what sub-benchmarks it has,
+# and should not print a final summary line.
+stdout -count=1 '^\s+BenchmarkX: x_test.go:13: LOG: X running N=1$'
+! stdout '^\s+BenchmarkX: x_test.go:13: LOG: X running N=\d\d+'
+! stdout 'BenchmarkX\s+\d+'
 
-#	BenchmarkXX is run but only with N=1, once
-stdout -count=1 '^    BenchmarkXX: z_test.go:18: LOG: XX running N=1$'
-! stdout  '^    BenchmarkXX: z_test.go:18: LOG: XX running N=10$'
+# Same for BenchmarkXX.
+stdout -count=1 '^\s+BenchmarkXX: z_test.go:18: LOG: XX running N=1$'
+! stdout  '^\s+BenchmarkXX: z_test.go:18: LOG: XX running N=\d\d+'
+! stdout 'BenchmarkXX\s+\d+'
 
-#	BenchmarkX/Y is run in full, twice
-stdout -count=2 '    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=10000\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100000000\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000000'
+# BenchmarkX/Y is run in full twice due to -count=2.
+# "Run in full" means that it runs for approximately the default benchtime,
+# but may cap out at N=1e9.
+# We don't actually care what the final iteration count is, but it should be
+# a large number, and the last iteration count prints right before the results.
+stdout -count=2 '^\s+BenchmarkX/Y: x_test.go:15: LOG: Y running N=[1-9]\d{4,}\nBenchmarkX/Y\s+\d+'
 
 -- testregexp/x_test.go --
 package x
@@ -65,4 +72,4 @@ func BenchmarkZ(b *testing.B) {
 
 func BenchmarkXX(b *testing.B) {
 	b.Logf("LOG: XX running N=%d", b.N)
-}
\ No newline at end of file
+}