diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/SMSService.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/SMSService.java
index 9e51e0c88..66813eb0d 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/SMSService.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/SMSService.java
@@ -452,11 +452,8 @@ public class SMSService extends XWService {
 
         byte[] data = bas.toByteArray();
 
-        boolean forceNow = cmd == SMS_CMD.INVITE || cmd == SMS_CMD.DATA;
-        // forceNow should always be true on first release since old code
-        // can't do the combined-messages stuff. Let's assert so we change
-        // when close to release.
-        Assert.assertTrue( BuildConfig.DEBUG );
+        boolean newSMSEnabled = XWPrefs.getSMSProtoEnabled( this );
+        boolean forceNow = !newSMSEnabled; // || cmd == SMS_CMD.INVITE;
         resendFor( phone, data, forceNow );
     }
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWPrefs.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWPrefs.java
index 5bad7482e..4de7cb416 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWPrefs.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWPrefs.java
@@ -82,6 +82,11 @@ public class XWPrefs {
         return getPrefsBoolean( context, R.string.key_enable_sms_toself, false );
     }
 
+    public static boolean getSMSProtoEnabled( Context context )
+    {
+        return getPrefsBoolean( context, R.string.key_enable_smsproto, false );
+    }
+
     public static boolean getHideNewgameButtons( Context context )
     {
         return getPrefsBoolean( context, R.string.key_hide_newgames,
diff --git a/xwords4/android/app/src/main/res/values/common_rsrc.xml b/xwords4/android/app/src/main/res/values/common_rsrc.xml
index 984ff5cdc..b776b8be4 100644
--- a/xwords4/android/app/src/main/res/values/common_rsrc.xml
+++ b/xwords4/android/app/src/main/res/values/common_rsrc.xml
@@ -125,6 +125,7 @@
   <string name="key_enable_dup_invite">key_enable_dup_invite</string>
   <string name="key_enable_nfc_toself">key_enable_nfc_toself</string>
   <string name="key_enable_sms_toself">key_enable_sms_toself</string>
+  <string name="key_enable_smsproto">key_enable_smsproto</string>
   <string name="key_ignore_gcm">key_ignore_gcm</string>
   <string name="key_show_gcm">key_show_gcm</string>
   <string name="key_nag_intervals">key_nag_intervals</string>
diff --git a/xwords4/android/app/src/main/res/values/strings.xml b/xwords4/android/app/src/main/res/values/strings.xml
index 8a35abac2..7427f169a 100644
--- a/xwords4/android/app/src/main/res/values/strings.xml
+++ b/xwords4/android/app/src/main/res/values/strings.xml
@@ -2516,6 +2516,10 @@
   <string name="nag_intervals">Reminder intervals (minutes1,minutes2,...)</string>
   <string name="enable_nfc_toself_title">Enable NFC to self</string>
   <string name="enable_nfc_toself_summary">Fake invitation to aid debugging</string>
+
+  <string name="enable_smsproto_title">Use new/experimental SMS code</string>
+  <string name="enable_smsproto_summary">(Requires that opponent be using it too)</string>
+
   <string name="enable_sms_toself_title">Short-circuit SMS to self</string>
   <string name="enable_sms_toself_summary">Skip radio when phone numbers same</string>
 
diff --git a/xwords4/android/app/src/main/res/xml/xwprefs.xml b/xwords4/android/app/src/main/res/xml/xwprefs.xml
index 8ea8c8a6d..8d6204d6d 100644
--- a/xwords4/android/app/src/main/res/xml/xwprefs.xml
+++ b/xwords4/android/app/src/main/res/xml/xwprefs.xml
@@ -437,6 +437,11 @@
     <PreferenceScreen android:title="@string/pref_group_sms_title"
                       android:summary="@string/pref_group_sms_summary"
                       >
+      <CheckBoxPreference android:key="@string/key_enable_smsproto"
+                          android:title="@string/enable_smsproto_title"
+                          android:summary="@string/enable_smsproto_summary"
+                          android:defaultValue="false"
+                          />
       <CheckBoxPreference android:key="@string/key_enable_sms_toself"
                           android:title="@string/enable_sms_toself_title"
                           android:summary="@string/enable_sms_toself_summary"