diff --git a/src/lsp/config.lsp.in b/src/lsp/config.lsp.in
index 5c4e0ae84..acfb05bbc 100644
--- a/src/lsp/config.lsp.in
+++ b/src/lsp/config.lsp.in
@@ -49,7 +49,7 @@ Returns, as a string, the location of the machine on which ECL runs."
 Returns the version of your ECL as a string."
   "@PACKAGE_VERSION@")
 
-(defun lisp-implementation-vcs-id ()
+(defun ext:lisp-implementation-vcs-id ()
   #.si::+commit-id+)
 
 (defun machine-type ()