diff --git a/go/loader/loader_test.go b/go/loader/loader_test.go
index 0b42e398d55..eb06f04d6c2 100644
--- a/go/loader/loader_test.go
+++ b/go/loader/loader_test.go
@@ -7,6 +7,7 @@ package loader_test
 import (
 	"fmt"
 	"go/build"
+	"path/filepath"
 	"reflect"
 	"sort"
 	"strings"
@@ -221,8 +222,9 @@ func TestLoad_ParseError_AllowErrors(t *testing.T) {
 	if len(badpkg.Files) != 1 {
 		t.Errorf("badpkg has %d files, want 1", len(badpkg.Files))
 	}
-	wantErr := "testdata/badpkgdecl.go:1:34: expected 'package', found 'EOF'"
+	wantErr := filepath.Join("testdata", "badpkgdecl.go") + ":1:34: expected 'package', found 'EOF'"
 	if !hasError(badpkg.Errors, wantErr) {
+
 		t.Errorf("badpkg.Errors = %v, want %s", badpkg.Errors, wantErr)
 	}
 }