diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index fe27ac6d48..ef6a724738 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -5576,13 +5576,13 @@ Route::filter_freq_controllable (bool hpf) const
 	}
 	if (hpf) {
 #ifdef MIXBUS32C
-		return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (eq->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, 6))); // HPF freq
+		return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (eq->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, 5))); // HPF freq
 #else
 		return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (eq->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, 2)));
 #endif
 	} else {
 #ifdef MIXBUS32C
-		return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (eq->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, 5))); // LPF freq
+		return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (eq->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, 6))); // LPF freq
 #else
 		return boost::shared_ptr<AutomationControl>();
 #endif