diff --git a/modules/lang/rust/autoload.el b/modules/lang/rust/autoload.el
index b52ddae2b..5d2333220 100644
--- a/modules/lang/rust/autoload.el
+++ b/modules/lang/rust/autoload.el
@@ -12,3 +12,11 @@
   "TODO"
   (let ((default-directory (+rust-cargo-project-p)))
     (compile command)))
+
+;;;###autoload
+(defun +rust-racer-lookup-documentation (identifier)
+  "A `+lookup/documentation' handler for Rust + Racer."
+  (let ((buf (racer--describe identifier)))
+    (when buf
+      (pop-to-buffer buf)
+      t)))
diff --git a/modules/lang/rust/config.el b/modules/lang/rust/config.el
index 1b8fceb9a..c199d2c4c 100644
--- a/modules/lang/rust/config.el
+++ b/modules/lang/rust/config.el
@@ -21,9 +21,9 @@
   :after rust-mode
   :config
   (add-hook 'rust-mode-hook #'racer-mode)
-  (set-lookup-handlers! 'rust-mode :async t
-    :definition #'racer-find-definition
-    :documentation #'racer-describe))
+  (set-lookup-handlers! 'rust-mode
+    :definition '(racer-find-definition :async t)
+    :documentation '+rust-racer-lookup-documentation))
 
 
 (def-package! flycheck-rust