diff --git a/module/language/elisp/runtime/function-slot.scm b/module/language/elisp/runtime/function-slot.scm
index 805f22a38..e2838b543 100644
--- a/module/language/elisp/runtime/function-slot.scm
+++ b/module/language/elisp/runtime/function-slot.scm
@@ -179,6 +179,8 @@
           ((zero? i) tail)
           (else (iterate (prim 1- i) (prim cdr tail))))))))
 
+(built-in-func length (@ (guile) length))
+
 
 ; Building lists.
 
diff --git a/test-suite/tests/elisp-compiler.test b/test-suite/tests/elisp-compiler.test
index e8bb46c88..7b879996c 100644
--- a/test-suite/tests/elisp-compiler.test
+++ b/test-suite/tests/elisp-compiler.test
@@ -553,6 +553,11 @@
          (equal (nthcdr 1 '(1 2 3)) '(2 3))
          (equal (nthcdr 2 '(1 2 3)) '(3))))
 
+  (pass-if "length"
+    (and (= (length '()) 0)
+         (= (length '(1 2 3 4 5)) 5)
+         (= (length '(1 2 (3 4 (5)) 6)) 4)))
+
   (pass-if "cons, list and make-list"
     (and (equal (cons 1 2) '(1 . 2)) (equal (cons 1 '(2 3)) '(1 2 3))
          (equal (cons 1 '()) '(1))