diff --git a/Language/Haskell/GhcMod/FillSig.hs b/Language/Haskell/GhcMod/FillSig.hs
index c9487e9..ae7e0ea 100644
--- a/Language/Haskell/GhcMod/FillSig.hs
+++ b/Language/Haskell/GhcMod/FillSig.hs
@@ -174,7 +174,7 @@ getSignatureFromHE file lineNo colNo = do
         dHeadTyVars (HE.DHParen _ r) = dHeadTyVars r
 #else
         dHeadTyVars :: HE.DeclHead l -> (HE.Name l, [HE.TyVarBind l])
-        dHeadTyVars (DHead _ n tys) = (n, tys)
+        dHeadTyVars (HE.DHead _ n tys) = (n, tys)
 #endif
 
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