diff --git a/module/system/base/compile.scm b/module/system/base/compile.scm
index 35dc0b197..b4dfbcd9d 100644
--- a/module/system/base/compile.scm
+++ b/module/system/base/compile.scm
@@ -117,7 +117,9 @@
                        (opts '())
                        (canonicalization 'relative))
   (with-fluids ((%file-port-name-canonicalization canonicalization))
-    (let* ((comp (or output-file (compiled-file-name file)))
+    (let* ((comp (or output-file (compiled-file-name file)
+                     (error "failed to create path for autocompiled file"
+                            file)))
            (in (open-input-file file))
            (enc (file-encoding in)))
       ;; Choose the input encoding deterministically.