diff --git a/semantic-ast/src/AST/GenerateSyntax.hs b/semantic-ast/src/AST/GenerateSyntax.hs
index 265863927..4900ca39e 100644
--- a/semantic-ast/src/AST/GenerateSyntax.hs
+++ b/semantic-ast/src/AST/GenerateSyntax.hs
@@ -120,10 +120,10 @@ makeHasFieldInstance ty param elim =
 
 -- | Create TH-generated SymbolMatching instances for sums, products, leaves
 symbolMatchingInstance :: [(String, Named)] -> Name -> Name -> Named -> DatatypeName -> Q [Dec]
-symbolMatchingInstance allSymbols extratypeParametername name named (DatatypeName str) = do
+symbolMatchingInstance allSymbols extraTypeParameterName name named (DatatypeName str) = do
   let tsSymbols = elemIndices (str, named) allSymbols
       names = intercalate ", " $ fmap (debugPrefix . (!!) allSymbols) tsSymbols
-  [d|instance TS.SymbolMatching ($(conT name) $(varT extratypeParametername)) where
+  [d|instance TS.SymbolMatching ($(conT name) $(varT extraTypeParameterName)) where
       matchedSymbols _   = tsSymbols
       showFailure _ node = "expected " <> $(litE (stringL names))
                         <> " but got " <> if nodeSymbol node == 65535 then "ERROR" else genericIndex debugSymbolNames (nodeSymbol node)