diff --git a/snapshot.yaml b/snapshot.yaml
deleted file mode 100644
index e98ce081f..000000000
--- a/snapshot.yaml
+++ /dev/null
@@ -1,9 +0,0 @@
-resolver: nightly-2017-09-10
-packages:
-- c-storable-deriving-0.1.3
-- cmark-gfm-0.1.3
-- Cabal-1.24.2.0
-- extra-1.5.3
-- process-1.4.3.0
-- optparse-applicative-0.13.2.0
-- netrc-0.2.0.0
diff --git a/src/Language/JSON/Grammar.hs b/src/Language/JSON/Grammar.hs
index adfc262b3..06b708cd3 100644
--- a/src/Language/JSON/Grammar.hs
+++ b/src/Language/JSON/Grammar.hs
@@ -5,6 +5,9 @@ import Language.Haskell.TH
 import TreeSitter.Language
 import TreeSitter.JSON
 
+-- Regenerate template haskell code when these files change:
+addDependentFileRelative "../../../vendor/haskell-tree-sitter/languages/json/vendor/tree-sitter-json/src/parser.c"
+
 -- | Statically-known rules corresponding to symbols in the grammar.
 -- v2 - bump this to regenerate
 mkSymbolDatatype (mkName "Grammar") tree_sitter_json