diff --git a/xwords4/android/XWords4/src/org/eehouse/android/xw4/BoardActivity.java b/xwords4/android/XWords4/src/org/eehouse/android/xw4/BoardActivity.java
index 73b348a86..09c1d9c97 100644
--- a/xwords4/android/XWords4/src/org/eehouse/android/xw4/BoardActivity.java
+++ b/xwords4/android/XWords4/src/org/eehouse/android/xw4/BoardActivity.java
@@ -161,6 +161,9 @@ public class BoardActivity extends Activity implements XW_UtilCtxt, Runnable {
         case R.id.board_menu_flip:
             m_jniThread.handle( JNIThread.JNICmd.CMD_FLIP );
             break;
+        case R.id.board_menu_trade:
+            m_jniThread.handle( JNIThread.JNICmd.CMD_TOGGLE_TRADE );
+            break;
         case R.id.board_menu_tray:
             m_jniThread.handle( JNIThread.JNICmd.CMD_TOGGLE_TRAY );
             break;
diff --git a/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/JNIThread.java b/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/JNIThread.java
index 937403b8b..8f2d5b5d2 100644
--- a/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/JNIThread.java
+++ b/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/JNIThread.java
@@ -23,6 +23,7 @@ public class JNIThread extends Thread {
             CMD_JUGGLE,
             CMD_FLIP,
             CMD_TOGGLE_TRAY,
+            CMD_TOGGLE_TRADE,
             CMD_UNDO_CUR,
             CMD_UNDO_LAST,
             CMD_HINT,
@@ -132,6 +133,9 @@ public class JNIThread extends Thread {
             case CMD_TOGGLE_TRAY:
                 draw = toggleTray();
                 break;
+            case CMD_TOGGLE_TRADE:
+                draw = XwJNI.board_beginTrade( m_jniGamePtr );
+                break;
             case CMD_UNDO_CUR:
                 draw = XwJNI.board_replaceTiles( m_jniGamePtr );
                 break;
diff --git a/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/XwJNI.java b/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/XwJNI.java
index 1b842905e..ae17a9ddc 100644
--- a/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/XwJNI.java
+++ b/xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/XwJNI.java
@@ -71,6 +71,7 @@ public class XwJNI {
     public static native void board_resetEngine( int gamePtr );
     public static native boolean board_requestHint( int gamePtr, boolean useTileLimits,
                                                     boolean[] workRemains );
+    public static native boolean board_beginTrade( int gamePtr );
 
     public static native void server_handleUndo( int gamePtr );
     public static native boolean server_do( int gamePtr );
diff --git a/xwords4/android/xwjni.c b/xwords4/android/xwjni.c
index 99894cd8f..0b5477937 100644
--- a/xwords4/android/xwjni.c
+++ b/xwords4/android/xwjni.c
@@ -445,6 +445,17 @@ Java_org_eehouse_android_xw4_jni_XwJNI_board_1showTray
     return result;
 }
 
+JNIEXPORT jboolean JNICALL
+Java_org_eehouse_android_xw4_jni_XwJNI_board_1beginTrade
+( JNIEnv* env, jclass C, jint gamePtr )
+{
+    jboolean result;
+    XWJNI_START();
+    result = board_beginTrade( state->game.board );
+    XWJNI_END();
+    return result;
+}
+
 JNIEXPORT jboolean JNICALL
 Java_org_eehouse_android_xw4_jni_XwJNI_board_1toggle_1showValues
 ( JNIEnv* env, jclass C, jint gamePtr )