diff --git a/src/runtime/haskell/PGF/VisualizeTree.hs b/src/runtime/haskell/PGF/VisualizeTree.hs
index 0597c1c52..916681d93 100644
--- a/src/runtime/haskell/PGF/VisualizeTree.hs
+++ b/src/runtime/haskell/PGF/VisualizeTree.hs
@@ -55,10 +55,12 @@ graphvizAbstractTree pgf (funs,cats) = render . tree2graph
 
     getAbs xs (EAbs _ x e) = getAbs (x:xs) e
     getAbs xs (ETyped e _) = getAbs xs e
+    getAbs xs (EImplArg e) = getAbs xs e
     getAbs xs e            = (xs,e)
     
     getApp (EApp x y)   es = getApp x (y:es)
     getApp (ETyped e _) es = getApp e es
+    getApp (EImplArg e) es = getApp e es
     getApp e            es = (e,es)
 
     getLbl scope (EFun f)     = let fun = if funs then ppCId f else empty