diff --git a/TODO.md b/TODO.md
index 1c1dacb..8c1ed0b 100644
--- a/TODO.md
+++ b/TODO.md
@@ -102,13 +102,15 @@ done, but these are the sort of enhancements I am thinking about.
     - [ ] fields
     - [ ] go to references of fields when tables are aliased
     - [ ] global search across other files
-- [ ] Options / Configuration
+- [X] Options / Configuration
     - [X] Configure over LSP
     - [X] Configure with some sort of per-project config file
     - [X] fennel/lua path
     - [X] lua version
     - [X] allowed global list
     - [X] enable/disable various linters
+    - [X] config validation
+    - [X] tests for config validation
 - [X] rename
     - [X] local symbols
     - [ ] module fields (may affect code behavior, may modify other files)
diff --git a/src/fennel-ls/docs.fnl b/src/fennel-ls/docs.fnl
index 3013a30..a7240d7 100644
--- a/src/fennel-ls/docs.fnl
+++ b/src/fennel-ls/docs.fnl
@@ -87,8 +87,6 @@
   (or (. specials builtin-name)
       (. macros* builtin-name)))
 
-;; TODO get-module-metadata
-
 (λ validate-config [configuration invalid]
   (when (not (. lua-versions configuration.lua-version))
     (invalid (.. "fennel-ls doesn't know about lua version "
diff --git a/test/settings.fnl b/test/settings.fnl
index 886a0ca..d40bfd7 100644
--- a/test/settings.fnl
+++ b/test/settings.fnl
@@ -63,7 +63,21 @@
     (local _ nil))
   nil)
 
+(fn test-config-validation []
+  (let [client (create-client {:main.fnl ""
+                               :flsproject.fnl "{:lua-version \"lua5.0\"}"})
+        [_init show] client.initialize-response]
+    (faith.= "window/showMessage" show.method)
+    (faith.match "doesn't know about lua version lua5.0" show.params.message))
+  (let [client (create-client {:main.fnl ""
+                               :flsproject.fnl "{:libraries {:nasilemak true}}"})
+        [_init show] client.initialize-response]
+    (faith.= "window/showMessage" show.method)
+    (faith.match "Could not find docset for library nasilemak"
+                 show.params.message)))
+
 {: test-path
  : test-extra-globals
  : test-lints
+ : test-config-validation
  : test-editing-settings}