diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index fc742b1..5069645 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -11,7 +11,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.17.x]
+        go-version: [1.16.x]
         os: [macos-11, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/libc_test.go b/libc_test.go
index d77d708..87f5b72 100644
--- a/libc_test.go
+++ b/libc_test.go
@@ -1,4 +1,5 @@
 //go:build darwin
+// +build darwin
 
 package libc
 
diff --git a/libtest_test.go b/libtest_test.go
index cef225f..6963a88 100644
--- a/libtest_test.go
+++ b/libtest_test.go
@@ -1,4 +1,5 @@
 //go:build darwin
+// +build darwin
 
 package libc_test