diff --git a/Changes.txt b/Changes.txt
index 9e0803d21..479bac355 100644
--- a/Changes.txt
+++ b/Changes.txt
@@ -20,7 +20,9 @@
     device.
 
   * Added ability to dynamically swap the port order of Stelladaptor/
-    2600-daptor devices with the 'Control-1' key combo.
+    2600-daptor devices with the 'Control-1' key combo (useful if you
+    have only one 2600-daptor and want to use it as a left port
+    normally, but as a right port for Star Raiders, etc).
 
   * Fixed bug in BoosterGrip controller emulation; the functionality
     of the booster and trigger buttons was reversed.  Related to this,
diff --git a/src/emucore/EventHandler.cxx b/src/emucore/EventHandler.cxx
index 84b6b461c..225237d5d 100644
--- a/src/emucore/EventHandler.cxx
+++ b/src/emucore/EventHandler.cxx
@@ -276,6 +276,19 @@ void EventHandler::mapStelladaptors(const string& saport)
     }
   }
   myOSystem->settings().setString("saport", saport);
+
+  // We're potentially swapping out an input device behind the back of
+  // the Event system, so we make sure all Stelladaptor-generated events
+  // are reset
+  for(int i = 0; i < 2; ++i)
+  {
+    for(int j = 0; j < 2; ++j)
+      myEvent.set(SA_Axis[i][j], 0);
+    for(int j = 0; j < 4; ++j)
+      myEvent.set(SA_Button[i][j], 0);
+    for(int j = 0; j < 12; ++j)
+      myEvent.set(SA_Key[i][j], 0);
+  }
 #endif
 }