diff --git a/ngcp/xavp.lua b/ngcp/xavp.lua
index b761b8a..a2e4edd 100644
--- a/ngcp/xavp.lua
+++ b/ngcp/xavp.lua
@@ -141,9 +141,14 @@ NGCPXAvp_MT = {
         end
     end
 
-    function NGCPXAvp:clean()
-        sr.pv.unset(string.format("$xavp(%s)", self.name))
-        sr.pv.sets(string.format("$xavp(%s=>dummy)", self.name), self.level)
+    function NGCPXAvp:clean(key)
+        if key then
+            local id = string.format("$xavp(%s[0]=>%s)", self.name, key)
+            sr.pv.unset(id)
+        else
+            sr.pv.unset(string.format("$xavp(%s)", self.name))
+            sr.pv.sets(string.format("$xavp(%s=>dummy)", self.name), self.level)
+        end
     end
 -- class
 --EOF
\ No newline at end of file
diff --git a/tests/ngcp_xavp.lua b/tests/ngcp_xavp.lua
index 4a0caf6..957336a 100644
--- a/tests/ngcp_xavp.lua
+++ b/tests/ngcp_xavp.lua
@@ -119,6 +119,20 @@ TestNGCPXAvp = {} --class
         assertEquals(sr.pv.get("$xavp(caller_peer=>dummy)"), "caller")
     end
 
+    function TestNGCPXAvp:test_clean_key()
+        local xavp = NGCPXAvp:new("caller", "peer", vals)
+        local vals = {1,"2",3,nil}
+        for i=1,#vals do
+            xavp("testid",vals[i])
+            assertEquals(xavp("testid"), vals[i])
+            assertEquals(sr.pv.get("$xavp(caller_peer=>testid)"),vals[i])
+        end
+        xavp("other", 1)
+        xavp:clean("testid")
+        assertIsNil(xavp("testid"))
+        assertEquals(sr.pv.get("$xavp(caller_peer=>other)"),1)
+    end
+
     function TestNGCPXAvp:test_tostring()
         local xavp = NGCPXAvp:new("caller", "peer", {})
         assertEquals(tostring(xavp), '{dummy="caller"}')