diff --git a/internal/gen.go b/internal/gen.go
index 7c239f9..3cd408b 100644
--- a/internal/gen.go
+++ b/internal/gen.go
@@ -65,6 +65,8 @@ type exportTemplateData struct {
 	VarNames  []string
 }
 
+var isAlphaNumeric = regexp.MustCompile(`^[a-zA-Z0-9]*$`)
+
 func generateFile(name string) string {
 	fmt.Println("generating file for dictionary " + name)
 
@@ -82,7 +84,7 @@ func generateFile(name string) string {
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		w := strings.TrimSpace(scanner.Text())
-		if regexp.MustCompile(`^[a-zA-Z0-9]*$`).MatchString(w) {
+		if isAlphaNumeric.MatchString(w) {
 			words = append(words, w)
 		}