diff --git a/src/syscall/time_js_wasm.s b/src/syscall/time_js_wasm.s
new file mode 100644
index 0000000000..f08b17006d
--- /dev/null
+++ b/src/syscall/time_js_wasm.s
@@ -0,0 +1,11 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+TEXT ·startTimer(SB),NOSPLIT,$0
+	JMP time·startTimer(SB)
+
+TEXT ·stopTimer(SB),NOSPLIT,$0
+	JMP time·stopTimer(SB)
diff --git a/src/syscall/timestruct.go b/src/syscall/timestruct.go
index 49c3383b4f..84a00a77d8 100644
--- a/src/syscall/timestruct.go
+++ b/src/syscall/timestruct.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
 
 package syscall
 
diff --git a/src/time/sys_unix.go b/src/time/sys_unix.go
index 0ef597fd9b..e064e0046c 100644
--- a/src/time/sys_unix.go
+++ b/src/time/sys_unix.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
 
 package time
 
diff --git a/src/time/zoneinfo_unix.go b/src/time/zoneinfo_unix.go
index 88313aa0ed..a37fd742df 100644
--- a/src/time/zoneinfo_unix.go
+++ b/src/time/zoneinfo_unix.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin,386 darwin,amd64 dragonfly freebsd linux,!android nacl netbsd openbsd solaris
+// +build darwin,386 darwin,amd64 dragonfly freebsd js,wasm linux,!android nacl netbsd openbsd solaris
 
 // Parse "zoneinfo" time zone file.
 // This is a fairly standard file format used on OS X, Linux, BSD, Sun, and others.