diff --git a/libs/ardour/ardour/uri_map.h b/libs/ardour/ardour/uri_map.h
index 9134c6be44..8f4f631e6f 100644
--- a/libs/ardour/ardour/uri_map.h
+++ b/libs/ardour/ardour/uri_map.h
@@ -28,14 +28,13 @@
 #include <glibmm/threads.h>
 
 #include "lv2.h"
-#include "lv2/lv2plug.in/ns/ext/uri-map/uri-map.h"
 #include "lv2/lv2plug.in/ns/ext/urid/urid.h"
 
 #include "ardour/libardour_visibility.h"
 
 namespace ARDOUR {
 
-/** Implementation of the LV2 uri-map and urid extensions.
+/** Implementation of the LV2 urid extension.
  *
  * This just uses a pair of std::map and is not so great in the space overhead
  * department, but it's fast enough and not really performance critical anyway.
@@ -46,7 +45,6 @@ public:
 
 	URIMap();
 
-	LV2_Feature* uri_map_feature()    { return &_uri_map_feature; }
 	LV2_Feature* urid_map_feature()   { return &_urid_map_feature; }
 	LV2_Feature* urid_unmap_feature() { return &_urid_unmap_feature; }
 
@@ -107,8 +105,6 @@ private:
 	Map   _map;
 	Unmap _unmap;
 
-	LV2_Feature         _uri_map_feature;
-	LV2_URI_Map_Feature _uri_map_feature_data;
 	LV2_Feature         _urid_map_feature;
 	LV2_URID_Map        _urid_map_feature_data;
 	LV2_Feature         _urid_unmap_feature;
diff --git a/libs/ardour/lv2_plugin.cc b/libs/ardour/lv2_plugin.cc
index 6b354fdd29..9dbba967d9 100644
--- a/libs/ardour/lv2_plugin.cc
+++ b/libs/ardour/lv2_plugin.cc
@@ -496,12 +496,11 @@ LV2Plugin::init(const void* c_plugin, samplecnt_t rate)
 	_features[0] = &_instance_access_feature;
 	_features[1] = &_data_access_feature;
 	_features[2] = &_make_path_feature;
-	_features[3] = _uri_map.uri_map_feature();
-	_features[4] = _uri_map.urid_map_feature();
-	_features[5] = _uri_map.urid_unmap_feature();
-	_features[6] = &_log_feature;
+	_features[3] = _uri_map.urid_map_feature();
+	_features[4] = _uri_map.urid_unmap_feature();
+	_features[5] = &_log_feature;
 
-	unsigned n_features = 7;
+	unsigned n_features = 6;
 	_features[n_features++] = &_def_state_feature;
 
 	lv2_atom_forge_init(&_impl->forge, _uri_map.urid_map());
@@ -2867,7 +2866,7 @@ LV2Plugin::connect_and_run(BufferSet& bufs,
 				 */
 				else if (atom->type == _uri_map.urids.atom_Blank ||
 				         atom->type == _uri_map.urids.atom_Object) {
-					LV2_Atom_Object* obj = (LV2_Atom_Object*)atom;
+					const LV2_Atom_Object* obj = (const LV2_Atom_Object*)atom;
 					if (obj->body.otype == _uri_map.urids.patch_Set) {
 						const LV2_Atom* property = NULL;
 						const LV2_Atom* value    = NULL;
@@ -3083,7 +3082,7 @@ LV2Plugin::connect_and_run(BufferSet& bufs,
 										_property_values[prop_id] = Variant(Variant::PATH, path);
 									}
 									if (value->type == _uri_map.urids.atom_Float) {
-										const float* val          = (float*)LV2_ATOM_BODY_CONST(value);
+										const float* val          = (const float*)LV2_ATOM_BODY_CONST(value);
 										_property_values[prop_id] = Variant(Variant::FLOAT, *val);
 									}
 									// TODO add support for other props (Int, Bool, ..)
diff --git a/libs/ardour/uri_map.cc b/libs/ardour/uri_map.cc
index 51c94e42a3..6d916e114f 100644
--- a/libs/ardour/uri_map.cc
+++ b/libs/ardour/uri_map.cc
@@ -85,28 +85,6 @@ URIMap::instance()
 	return *URIMap::uri_map;
 }
 
-static uint32_t
-c_uri_map_uri_to_id(LV2_URI_Map_Callback_Data callback_data,
-                    const char*               map,
-                    const char*               uri)
-{
-	URIMap* const me = (URIMap*)callback_data;
-	const uint32_t id = me->uri_to_id(uri);
-
-	/* The event context with the uri-map extension guarantees a value in the
-	   range of uint16_t.  Ardour used to map to a separate range to achieve
-	   this, but unfortunately some plugins are broken and use the incorrect
-	   context.  To compensate, we simply use the same context for everything
-	   and hope that anything in the event context gets mapped before
-	   UINT16_MAX is reached (which will be fine unless something seriously
-	   weird is going on).  If this fails there is nothing we can do, die.
-	*/
-	assert(!map || strcmp(map, "http://lv2plug.in/ns/ext/event")
-	       || id < UINT16_MAX);
-
-	return id;
-}
-
 static LV2_URID
 c_urid_map(LV2_URID_Map_Handle handle,
            const char*         uri)
@@ -125,11 +103,6 @@ c_urid_unmap(LV2_URID_Unmap_Handle handle,
 
 URIMap::URIMap()
 {
-	_uri_map_feature_data.uri_to_id     = c_uri_map_uri_to_id;
-	_uri_map_feature_data.callback_data = this;
-	_uri_map_feature.URI                = LV2_URI_MAP_URI;
-	_uri_map_feature.data               = &_uri_map_feature_data;
-
 	_urid_map_feature_data.map    = c_urid_map;
 	_urid_map_feature_data.handle = this;
 	_urid_map_feature.URI         = LV2_URID_MAP_URI;