diff --git a/lsp-test.cabal b/lsp-test.cabal
index 1c8350a..4d96585 100644
--- a/lsp-test.cabal
+++ b/lsp-test.cabal
@@ -37,6 +37,7 @@ library
   default-language:    Haskell2010
   build-depends:       base >= 4.10 && < 5
                      , lsp == 0.18.*
+                     , lsp-types
                      , aeson
                      , aeson-pretty
                      , ansi-terminal