diff --git a/lib/galaxy/tools/parameters/basic.py b/lib/galaxy/tools/parameters/basic.py
index 208255f141c..1342b4a50cf 100644
--- a/lib/galaxy/tools/parameters/basic.py
+++ b/lib/galaxy/tools/parameters/basic.py
@@ -484,8 +484,12 @@ class SelectToolParameter( ToolParameter ):
         else:
             return self.static_options
     def get_legal_values( self, trans, other_values ):
+        def _get_UnvalidatedValue_value( value ):
+            if isinstance( value, UnvalidatedValue ):
+                return value.value
+            return value
         if self.options:
-            return set( v for _, v, _ in self.options.get_options( trans, other_values ) )
+            return map( _get_UnvalidatedValue_value, set( v for _, v, _ in self.options.get_options( trans, other_values ) ) )
         elif self.dynamic_options:
             return set( v for _, v, _ in eval( self.dynamic_options, self.tool.code_namespace, other_values ) )
         else:
@@ -510,6 +514,9 @@ class SelectToolParameter( ToolParameter ):
         field = form_builder.SelectField( self.name, self.multiple, self.display, self.refresh_on_change )
         options = self.get_options( trans, other_values )
         for text, optval, selected in options:
+            if isinstance( optval, UnvalidatedValue ):
+                optval = optval.value
+                text = "%s (unvalidated)" % text
             if value: 
                 selected = ( optval in value )
             field.add_option( text, optval, selected )
diff --git a/lib/galaxy/tools/parameters/dynamic_options.py b/lib/galaxy/tools/parameters/dynamic_options.py
index 328e01c7327..83e7c933a35 100644
--- a/lib/galaxy/tools/parameters/dynamic_options.py
+++ b/lib/galaxy/tools/parameters/dynamic_options.py
@@ -108,7 +108,8 @@ class DataMetaFilter( Filter ):
         if not isinstance( ref, self.dynamic_option.tool_param.tool.app.model.HistoryDatasetAssociation ):
             return [] #not a valid dataset
         meta_value = ref.metadata.get( self.key, None )
-        assert meta_value is not None, "Required metadata value '%s' not found in referenced dataset" % self.key
+        if meta_value is None: #assert meta_value is not None, "Required metadata value '%s' not found in referenced dataset" % self.key
+            return [ ( disp_name, basic.UnvalidatedValue( optval ), selected ) for disp_name, optval, selected in options ]
         
         if self.column is not None:
             rval = []