diff --git a/distrho/src/DistrhoPluginVST2.cpp b/distrho/src/DistrhoPluginVST2.cpp
index 6afa717f..341c3035 100644
--- a/distrho/src/DistrhoPluginVST2.cpp
+++ b/distrho/src/DistrhoPluginVST2.cpp
@@ -59,6 +59,7 @@
 #define effGetProgramNameIndexed 29
 #define effGetPlugCategory 35
 #define effVendorSpecific 50
+#define effKeysRequired 57
 #define effEditKeyDown 59
 #define effEditKeyUp 60
 #define kVstVersion 2400
@@ -761,6 +762,9 @@ public:
             break;
 
 # if !DISTRHO_PLUGIN_HAS_EXTERNAL_UI
+        case effKeysRequired:
+            return 1;
+
         case effEditKeyDown:
             if (fVstUI != nullptr)
                 return fVstUI->handlePluginKeyEvent(true, index, value);