diff --git a/interfacer/src/browsh/firefox.go b/interfacer/src/browsh/firefox.go
index 6108ba79..e9c8a7d5 100644
--- a/interfacer/src/browsh/firefox.go
+++ b/interfacer/src/browsh/firefox.go
@@ -231,10 +231,11 @@ func installWebextension() {
 		Shutdown(err)
 	}
 	file, err := ioutil.TempFile(os.TempDir(), "browsh-webext-addon")
-	defer os.Remove(file.Name())
 	ioutil.WriteFile(file.Name(), []byte(data), 0644)
 	args := map[string]interface{}{"path": file.Name()}
 	sendFirefoxCommand("Addon:Install", args)
+	time.Sleep(100 * time.Millisecond)
+	defer os.Remove(file.Name())
 }
 
 // Set a Firefox preference as you would in `about:config`
diff --git a/interfacer/src/browsh/version.go b/interfacer/src/browsh/version.go
index 0d87838c..5aaaa2fc 100644
--- a/interfacer/src/browsh/version.go
+++ b/interfacer/src/browsh/version.go
@@ -1,3 +1,3 @@
 package browsh
 
-var browshVersion = "1.6.2"
+var browshVersion = "1.6.3"