diff --git a/libs/ardour/plugin_insert.cc b/libs/ardour/plugin_insert.cc
index 25f700b7ca..996d3d7dbf 100644
--- a/libs/ardour/plugin_insert.cc
+++ b/libs/ardour/plugin_insert.cc
@@ -934,9 +934,9 @@ PluginInsert::set_parameter_state_2X (const XMLNode& node, int version)
 		XMLNode *child;
 		const char *port;
 		uint32_t port_id;
-		
+
 		cnodes = (*niter)->children ("port");
-		
+
 		for (iter = cnodes.begin(); iter != cnodes.end(); ++iter){
 			
 			child = *iter;
@@ -961,6 +961,30 @@ PluginInsert::set_parameter_state_2X (const XMLNode& node, int version)
 			if (c) {
 				if (!child->children().empty()) {
 					c->alist()->set_state (*child->children().front(), version);
+
+					/* In some cases 2.X saves lists with min_yval and max_yval
+					   being FLT_MIN and FLT_MAX respectively.  This causes problems
+					   in A3 because these min/max values are used to compute
+					   where GUI control points should be drawn.  If we see such
+					   values, `correct' them to the min/max of the appropriate
+					   parameter.
+					*/
+
+					float min_y = c->alist()->get_min_y ();
+					float max_y = c->alist()->get_max_y ();
+
+					Plugin::ParameterDescriptor desc;
+					_plugins.front()->get_parameter_descriptor (port_id, desc);
+
+					if (min_y == FLT_MIN) {
+						min_y = desc.lower;
+					}
+					
+					if (max_y == FLT_MAX) {
+						max_y = desc.upper;
+					}
+
+					c->alist()->set_yrange (min_y, max_y);
 				}
 			} else {
 				error << string_compose (_("PluginInsert: automatable control %1 not found - ignored"), port_id) << endmsg;