diff --git a/src/android/InAppBrowser.java b/src/android/InAppBrowser.java
index e630928..9a695db 100644
--- a/src/android/InAppBrowser.java
+++ b/src/android/InAppBrowser.java
@@ -1112,7 +1112,7 @@ public class InAppBrowser extends CordovaPlugin {
                 }
             }
             // Test for whitelisted custom scheme names like mycoolapp:// or twitteroauthresponse:// (Twitter Oauth Response)
-            else if (!url.startsWith("http:") && !url.startsWith("https:") && url.matches("^[a-z]*://.*?$")) {
+            else if (!url.startsWith("http:") && !url.startsWith("https:") && url.matches("^[A-Za-z0-9+.-]*://.*?$")) {
                 if (allowedSchemes == null) {
                     String allowed = preferences.getString("AllowedSchemes", null);
                     if(allowed != null) {