diff --git a/go/callgraph/cha/testdata/func.go b/go/callgraph/cha/testdata/func.go
index ad483f100d..a12f3f1fd3 100644
--- a/go/callgraph/cha/testdata/func.go
+++ b/go/callgraph/cha/testdata/func.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/callgraph/cha/testdata/iface.go b/go/callgraph/cha/testdata/iface.go
index 1622ec154a..8ca65e160a 100644
--- a/go/callgraph/cha/testdata/iface.go
+++ b/go/callgraph/cha/testdata/iface.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/callgraph/cha/testdata/recv.go b/go/callgraph/cha/testdata/recv.go
index 5ba48e933f..a92255e06d 100644
--- a/go/callgraph/cha/testdata/recv.go
+++ b/go/callgraph/cha/testdata/recv.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/callgraph/rta/testdata/func.go b/go/callgraph/rta/testdata/func.go
index 968c73d80e..7b6870901b 100644
--- a/go/callgraph/rta/testdata/func.go
+++ b/go/callgraph/rta/testdata/func.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/callgraph/rta/testdata/iface.go b/go/callgraph/rta/testdata/iface.go
index c3ee57049f..8f84c93077 100644
--- a/go/callgraph/rta/testdata/iface.go
+++ b/go/callgraph/rta/testdata/iface.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/callgraph/rta/testdata/rtype.go b/go/callgraph/rta/testdata/rtype.go
index 85414e5530..9e8f35dea9 100644
--- a/go/callgraph/rta/testdata/rtype.go
+++ b/go/callgraph/rta/testdata/rtype.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/ssa/identical_test.go b/go/ssa/identical_test.go
index 404693dcd6..d194b70e91 100644
--- a/go/ssa/identical_test.go
+++ b/go/ssa/identical_test.go
@@ -1,4 +1,4 @@
-//+build go1.8
+// +build go1.8
 
 package ssa_test
 
diff --git a/go/ssa/testdata/objlookup.go b/go/ssa/testdata/objlookup.go
index d110add69a..b040d74733 100644
--- a/go/ssa/testdata/objlookup.go
+++ b/go/ssa/testdata/objlookup.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main
 
diff --git a/go/ssa/testdata/structconv.go b/go/ssa/testdata/structconv.go
index 31264691bb..c0b4b840ee 100644
--- a/go/ssa/testdata/structconv.go
+++ b/go/ssa/testdata/structconv.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 // This file is the input to TestValueForExprStructConv in identical_test.go,
 // which uses the same framework as TestValueForExpr does in source_test.go.
diff --git a/go/ssa/testdata/valueforexpr.go b/go/ssa/testdata/valueforexpr.go
index fe65b94f7f..da76f13a39 100644
--- a/go/ssa/testdata/valueforexpr.go
+++ b/go/ssa/testdata/valueforexpr.go
@@ -1,4 +1,4 @@
-//+build ignore
+// +build ignore
 
 package main