diff --git a/Rubberduck.Core/UI/SelectionChangeService.cs b/Rubberduck.Core/UI/SelectionChangeService.cs
index 3e15f475ef..cb25628731 100644
--- a/Rubberduck.Core/UI/SelectionChangeService.cs
+++ b/Rubberduck.Core/UI/SelectionChangeService.cs
@@ -40,6 +40,7 @@ private void OnVbeSelectionChanged(object sender, EventArgs e)
         {
             Task.Run(() =>
             {
+                
                 var selectedDeclaration = _selectedDeclarationProvider.SelectedDeclaration();
                 var eventArgs = new DeclarationChangedEventArgs(_vbe, selectedDeclaration);
                 DispatchSelectedDeclaration(eventArgs);
diff --git a/Rubberduck.Parsing/VBA/DeclarationCaching/DeclarationFinder.cs b/Rubberduck.Parsing/VBA/DeclarationCaching/DeclarationFinder.cs
index bb1cc114fd..ba4c637069 100644
--- a/Rubberduck.Parsing/VBA/DeclarationCaching/DeclarationFinder.cs
+++ b/Rubberduck.Parsing/VBA/DeclarationCaching/DeclarationFinder.cs
@@ -640,14 +640,13 @@ public ParameterDeclaration FindParameterOfNonDefaultMemberFromSimpleArgumentNot
             {
                 // argument is positional: work out its index
                 var argumentList = argumentExpression.GetAncestor<VBAParser.ArgumentListContext>();
-                var arguments = argumentList.GetDescendents<VBAParser.PositionalArgumentContext>().ToArray();
+                var arguments = argumentList.children.Where(t => (t is VBAParser.ArgumentContext)).ToArray();
 
                 var parameterIndex = arguments
-                    .Select((arg, index) => arg.GetDescendent<VBAParser.ArgumentExpressionContext>() == argumentExpression ? (arg, index) : (null, -1))
-                    .SingleOrDefault(item => item.arg != null).index;
+                    .Select((arg, index) => (arg: arg as ParserRuleContext, index))
+                    .SingleOrDefault(item => item.arg.ContainsTokenIndex(argumentExpression.Start.TokenIndex)).index;
 
                 parameter = parameters
-                    .OrderBy(p => p.Selection)
                     .Select((param, index) => (param, index))
                     .SingleOrDefault(item => item.index == parameterIndex).param;
             }
diff --git a/Rubberduck.Parsing/VBA/SelectedDeclarationProvider.cs b/Rubberduck.Parsing/VBA/SelectedDeclarationProvider.cs
index d459e1ee05..162580cbf9 100644
--- a/Rubberduck.Parsing/VBA/SelectedDeclarationProvider.cs
+++ b/Rubberduck.Parsing/VBA/SelectedDeclarationProvider.cs
@@ -84,6 +84,12 @@ public Declaration SelectedDeclaration(QualifiedSelection qualifiedSelection)
                 return candidateViaConstantDeclaration;
             }
 
+            var candidateViaArgumentCallSite = SelectedDeclarationViaArgument(qualifiedSelection, finder);
+            if (candidateViaArgumentCallSite != null)
+            {
+                return candidateViaArgumentCallSite;
+            }
+
             var candidateViaContainingMember = SelectedMember(qualifiedSelection);
             if (candidateViaContainingMember != null)
             {
@@ -93,6 +99,21 @@ public Declaration SelectedDeclaration(QualifiedSelection qualifiedSelection)
             return SelectedModule(qualifiedSelection);
         }
 
+        private static ParameterDeclaration SelectedDeclarationViaArgument(QualifiedSelection qualifiedSelection, DeclarationFinder finder)
+        {
+            var members = finder.Members(qualifiedSelection.QualifiedName).Where(m => m.DeclarationType.HasFlag(DeclarationType.Procedure));
+            var enclosingProcedure = members.SingleOrDefault(m => m.Context.GetSelection().Contains(qualifiedSelection.Selection));
+            var context = enclosingProcedure?.Context.GetDescendents<VBAParser.ArgumentExpressionContext>()
+                .FirstOrDefault(m => m.GetSelection().ContainsFirstCharacter(qualifiedSelection.Selection));
+
+            if (context != null)
+            {
+                return finder.FindParameterOfNonDefaultMemberFromSimpleArgumentNotPassedByValExplicitly(context, enclosingProcedure);
+            }
+
+            return null;
+        }
+
         private static Declaration SelectedDeclarationViaReference(QualifiedSelection qualifiedSelection, DeclarationFinder finder)
         {
             var referencesInModule = finder.IdentifierReferences(qualifiedSelection.QualifiedName);