diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..f517224
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/slory7/pkgconfig
+
+go 1.14
diff --git a/gopath.go b/gopath.go
index 85f5e23..9161423 100644
--- a/gopath.go
+++ b/gopath.go
@@ -87,7 +87,7 @@ func LookupGopath(pkg string) (*PC, error) {
 	)
 	look := func(path, _, lib string) bool {
 		file := filepath.Join(lib, pkg+".pc")
-		vars["GOPATH"] = path
+		vars["GOPATH"] = filepath.ToSlash(path)
 		if f, err = os.Open(file); err == nil {
 			pc, err = NewPCVars(f, vars)
 			f.Close()