diff --git a/.circleci/config.yml b/.circleci/config.yml
index 3fb1d5d..88fbcd3 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -22,7 +22,7 @@ jobs:
     environment:
       TEST_RES_DIR: /tmp/test-results
       ARTIFACTS_DIR: /tmp/artifacts
-      APP_VERSION: v0.4.1
+      APP_VERSION: v0.5.0
     steps:
       - checkout
       - run:
diff --git a/applescriptHandler.go b/applescriptHandler.go
index 6f35863..c3a0e35 100644
--- a/applescriptHandler.go
+++ b/applescriptHandler.go
@@ -31,10 +31,14 @@ end tell
 func CloseApp(appName string, reschan chan string, errchan chan error) func() {
 	return func() {
 		script := fmt.Sprintf(`
-tell application "%s"
-	quit
-end tell
-		`, appName)
+if exists application "%s" then
+  tell application "%s"
+    quit
+  end tell
+else
+  error "could not close app '%s, because it cannot be found" 
+end if 
+		`, appName, appName, appName)
 
 		err := executeAppleScript(script)