diff --git a/parser/parser.go b/parser/parser.go
index b8b9852..1c0b94c 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -1,13 +1,9 @@
 package parser
 
 import (
-	"fmt"
 	"go/ast"
 	"go/parser"
 	"go/token"
-	"os"
-	"path"
-	"path/filepath"
 	"strings"
 )
 
@@ -93,29 +89,3 @@ func (p *Parser) Parse(fname string, isDir bool) error {
 	}
 	return nil
 }
-
-func getPkgPath(fname string, isDir bool) (string, error) {
-	fname, err := filepath.Abs(fname)
-	if err != nil {
-		return "", err
-	}
-
-	for _, p := range filepath.SplitList(os.Getenv("GOPATH")) {
-		gopath := filepath.Join(p, "src")
-		pkg, err := filepath.Rel(gopath, fname)
-		if err != nil {
-			continue
-		}
-
-		if pkg != fname {
-			p := normalizePath(pkg)
-
-			if !isDir {
-				return path.Dir(p), nil
-			}
-			return p, nil
-		}
-	}
-
-	return "", fmt.Errorf("file '%v' is not in GOPATH", fname)
-}
diff --git a/parser/parser_test.go b/parser/parser_test.go
deleted file mode 100644
index 7be4654..0000000
--- a/parser/parser_test.go
+++ /dev/null
@@ -1,26 +0,0 @@
-package parser
-
-import "testing"
-
-func TestGetPkgPath(t *testing.T) {
-	cases := []struct {
-		fname string
-		isDir bool
-	}{
-		{"parser.go", false},
-		{".", true},
-	}
-	exp := "github.com/mailru/easyjson/parser"
-
-	for _, tc := range cases {
-
-		pkg, err := getPkgPath(tc.fname, tc.isDir)
-		if err != nil {
-			t.Error(err)
-		}
-		if pkg != exp {
-			t.Errorf("in: \"%s\" isDir: %v want: %s got: %s", tc.fname, tc.isDir, exp, pkg)
-		}
-	}
-
-}
diff --git a/parser/parser_unix.go b/parser/parser_unix.go
index a5a9451..a1b9d84 100644
--- a/parser/parser_unix.go
+++ b/parser/parser_unix.go
@@ -2,6 +2,32 @@
 
 package parser
 
-func normalizePath(path string) string {
-	return path
+import (
+	"fmt"
+	"os"
+	"path"
+	"strings"
+)
+
+func getPkgPath(fname string, isDir bool) (string, error) {
+	if !path.IsAbs(fname) {
+		pwd, err := os.Getwd()
+		if err != nil {
+			return "", err
+		}
+		fname = path.Join(pwd, fname)
+	}
+
+	for _, p := range strings.Split(os.Getenv("GOPATH"), ":") {
+		prefix := path.Join(p, "src") + "/"
+		if rel := strings.TrimPrefix(fname, prefix); rel != fname {
+			if !isDir {
+				return path.Dir(rel), nil
+			} else {
+				return path.Clean(rel), nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("file '%v' is not in GOPATH", fname)
 }
diff --git a/parser/parser_windows.go b/parser/parser_windows.go
index cd4be7c..64974aa 100644
--- a/parser/parser_windows.go
+++ b/parser/parser_windows.go
@@ -1,9 +1,37 @@
-package parser
-
-import (
-	"strings"
-)
-
-func normalizePath(path string) string {
-	return strings.Replace(path, "\\", "/", -1)
-}
+package parser
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"strings"
+)
+
+func normalizePath(path string) string {
+	return strings.Replace(path, "\\", "/", -1)
+}
+
+func getPkgPath(fname string, isDir bool) (string, error) {
+	if !path.IsAbs(fname) {
+		pwd, err := os.Getwd()
+		if err != nil {
+			return "", err
+		}
+		fname = path.Join(pwd, fname)
+	}
+
+	fname = normalizePath(fname)
+
+	for _, p := range strings.Split(os.Getenv("GOPATH"), ";") {
+		prefix := path.Join(normalizePath(p), "src") + "/"
+		if rel := strings.TrimPrefix(fname, prefix); rel != fname {
+			if !isDir {
+				return path.Dir(rel), nil
+			} else {
+				return path.Clean(rel), nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("file '%v' is not in GOPATH", fname)
+}