diff --git a/cli/xgotext/README.md b/cli/xgotext/README.md
index 3ec29dd..e488c39 100644
--- a/cli/xgotext/README.md
+++ b/cli/xgotext/README.md
@@ -1,6 +1,6 @@
 # xgotext
 
-CLI tool to extract translation strings from Go packages into .PO files. 
+CLI tool to extract translation strings from Go packages into .POT files. 
 
 ## Installation
 
@@ -11,7 +11,15 @@ go install github.com/leonelquinteros/gotext/cli/xgotext
 ## Usage
 
 ```
-xgotext -in /path/to/go/package -out /path/to/output/dir
+Usage of xgotext:
+  -default string
+        Name of default domain (default "default")
+  -exclude string
+        Comma separated list of directories to exclude (default ".git")
+  -in string
+        input dir: /path/to/go/pkg
+  -out string
+        output dir: /path/to/i18n/files
 ```
 
 ## Implementation
@@ -27,7 +35,7 @@ Isn't able to parse calls to translation functions using parameters inside varia
 gotext.Get("Translate this")
 
 tr := "Translate this string"
-// The following line will NOT be added to the .po file
+// The following line will NOT be added to the .pot file
 gotext.Get(tr)
 ```
 
diff --git a/cli/xgotext/fixtures/main.go b/cli/xgotext/fixtures/main.go
index 19b0b0a..29944d1 100644
--- a/cli/xgotext/fixtures/main.go
+++ b/cli/xgotext/fixtures/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/leonelquinteros/gotext"
@@ -78,6 +79,9 @@ func main() {
 	// redefine alias with fake struct
 	alias := Fake2{}
 	alias.Get("3")
+
+	err := errors.New("test")
+	fmt.Print(err.Error())
 }
 
 // dummy function
diff --git a/cli/xgotext/main.go b/cli/xgotext/main.go
index 17ef313..fa12cd4 100644
--- a/cli/xgotext/main.go
+++ b/cli/xgotext/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"log"
+	"strings"
 
 	"github.com/leonelquinteros/gotext/cli/xgotext/parser"
 )
@@ -11,6 +12,7 @@ var (
 	dirName       = flag.String("in", "", "input dir: /path/to/go/pkg")
 	outputDir     = flag.String("out", "", "output dir: /path/to/i18n/files")
 	defaultDomain = flag.String("default", "default", "Name of default domain")
+	excludeDirs   = flag.String("exclude", ".git", "Comma separated list of directories to exclude")
 )
 
 func main() {
@@ -30,7 +32,7 @@ func main() {
 		Default: *defaultDomain,
 	}
 
-	err := parser.ParseDirRec(*dirName, data)
+	err := parser.ParseDirRec(*dirName, strings.Split(*excludeDirs, ","), data)
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/cli/xgotext/parser/domain.go b/cli/xgotext/parser/domain.go
index 08c1765..55ff4a5 100644
--- a/cli/xgotext/parser/domain.go
+++ b/cli/xgotext/parser/domain.go
@@ -186,7 +186,7 @@ func (m *DomainMap) Save(directory string) error {
 
 	// save each domain in a separate po file
 	for name, domain := range m.Domains {
-		err := domain.Save(filepath.Join(directory, name+".po"))
+		err := domain.Save(filepath.Join(directory, name+".pot"))
 		if err != nil {
 			return fmt.Errorf("failed to save domain %s: %v", name, err)
 		}
diff --git a/cli/xgotext/parser/golang.go b/cli/xgotext/parser/golang.go
index 62fbdd9..2693503 100644
--- a/cli/xgotext/parser/golang.go
+++ b/cli/xgotext/parser/golang.go
@@ -165,7 +165,7 @@ func (g *GoFile) checkType(rawType types.Type) bool {
 		return g.checkType(t.Elem())
 
 	case *types.Named:
-		if t.Obj().Pkg().Path() != "github.com/leonelquinteros/gotext" {
+		if t.Obj().Pkg() == nil || t.Obj().Pkg().Path() != "github.com/leonelquinteros/gotext" {
 			return false
 		}
 	default:
@@ -193,7 +193,8 @@ func (g *GoFile) inspectCallExpr(n *ast.CallExpr) {
 
 		} else {
 			// validate type of object
-			if !g.checkType(g.getType(e).Type()) {
+			t := g.getType(e)
+			if t == nil || !g.checkType(t.Type()) {
 				return
 			}
 		}
@@ -201,7 +202,8 @@ func (g *GoFile) inspectCallExpr(n *ast.CallExpr) {
 	// call to attribute
 	case *ast.SelectorExpr:
 		// validate type of object
-		if !g.checkType(g.getType(e.Sel).Type()) {
+		t := g.getType(e.Sel)
+		if t == nil || !g.checkType(t.Type()) {
 			return
 		}
 
diff --git a/cli/xgotext/parser/parser.go b/cli/xgotext/parser/parser.go
index 9f12e1b..4fdd2d3 100644
--- a/cli/xgotext/parser/parser.go
+++ b/cli/xgotext/parser/parser.go
@@ -1,8 +1,10 @@
 package parser
 
 import (
+	"log"
 	"os"
 	"path/filepath"
+	"strings"
 )
 
 // ParseDirFunc parses one directory
@@ -34,7 +36,7 @@ func ParseDir(dirPath, basePath string, data *DomainMap) error {
 }
 
 // ParseDirRec calls all known parser for each directory
-func ParseDirRec(dirPath string, data *DomainMap) error {
+func ParseDirRec(dirPath string, exclude []string, data *DomainMap) error {
 	dirPath, _ = filepath.Abs(dirPath)
 
 	err := filepath.Walk(dirPath, func(path string, info os.FileInfo, err error) error {
@@ -43,6 +45,15 @@ func ParseDirRec(dirPath string, data *DomainMap) error {
 		}
 
 		if info.IsDir() {
+			// skip directory if in exclude list
+			subDir, _ := filepath.Rel(dirPath, path)
+			for _, d := range exclude {
+				if strings.HasPrefix(subDir, d) {
+					return nil
+				}
+			}
+			log.Print(path)
+
 			err := ParseDir(path, dirPath, data)
 			if err != nil {
 				return err