diff --git a/distrho/src/DistrhoPluginInternal.hpp b/distrho/src/DistrhoPluginInternal.hpp
index bbb107913..d9677c140 100644
--- a/distrho/src/DistrhoPluginInternal.hpp
+++ b/distrho/src/DistrhoPluginInternal.hpp
@@ -43,6 +43,7 @@ struct Plugin::PrivateData {
 #endif
 
     uint32_t   parameterCount;
+    uint32_t   parameterOffset;
     Parameter* parameters;
 
 #if DISTRHO_PLUGIN_WANT_PROGRAMS
@@ -73,6 +74,7 @@ struct Plugin::PrivateData {
           audioPorts(nullptr),
 #endif
           parameterCount(0),
+          parameterOffset(0),
           parameters(nullptr),
 #if DISTRHO_PLUGIN_WANT_PROGRAMS
           programCount(0),
@@ -91,6 +93,22 @@ struct Plugin::PrivateData {
     {
         DISTRHO_SAFE_ASSERT(bufferSize != 0);
         DISTRHO_SAFE_ASSERT(d_isNotZero(sampleRate));
+
+#if defined(DISTRHO_PLUGIN_TARGET_DSSI) || defined(DISTRHO_PLUGIN_TARGET_LV2)
+        parameterOffset += DISTRHO_PLUGIN_NUM_INPUTS + DISTRHO_PLUGIN_NUM_OUTPUTS;
+# if DISTRHO_PLUGIN_WANT_LATENCY
+        parameterOffset += 1;
+# endif
+#endif
+
+#ifdef DISTRHO_PLUGIN_TARGET_LV2
+# if (DISTRHO_PLUGIN_IS_SYNTH || DISTRHO_PLUGIN_WANT_TIMEPOS || DISTRHO_PLUGIN_WANT_STATE)
+        parameterOffset += 1;
+#  if DISTRHO_PLUGIN_WANT_STATE
+        parameterOffset += 1;
+#  endif
+# endif
+#endif
     }
 
     ~PrivateData() noexcept
@@ -283,6 +301,13 @@ class PluginExporter
         return fData->parameterCount;
     }
 
+    uint32_t getParameterOffset() const noexcept
+    {
+        DISTRHO_SAFE_ASSERT_RETURN(fData != nullptr, 0);
+
+        return fData->parameterOffset;
+    }
+
     uint32_t getParameterHints(const uint32_t index) const noexcept
     {
         DISTRHO_SAFE_ASSERT_RETURN(fData != nullptr && index < fData->parameterCount, 0x0);
diff --git a/distrho/src/DistrhoPluginLADSPA+DSSI.cpp b/distrho/src/DistrhoPluginLADSPA+DSSI.cpp
index 2e2091c77..01bb19d7f 100644
--- a/distrho/src/DistrhoPluginLADSPA+DSSI.cpp
+++ b/distrho/src/DistrhoPluginLADSPA+DSSI.cpp
@@ -331,7 +331,12 @@ class PluginLadspaDssi
 
     int dssi_get_midi_controller_for_port(const ulong port) noexcept
     {
-        const uint8_t midiCC = fPlugin.getParameterMidiCC(port);
+        const uint32_t parameterOffset = fPlugin.getParameterOffset();
+
+        if (port > parameterOffset)
+            return DSSI_NONE;
+
+        const uint8_t midiCC = fPlugin.getParameterMidiCC(port-parameterOffset);
 
         if (midiCC == 0 || midiCC == 32 || midiCC >= 0x78)
             return DSSI_NONE;