diff --git a/gnu/packages/aux-files/run-in-namespace.c b/gnu/packages/aux-files/run-in-namespace.c
index 52a16a5362..947ff02dda 100644
--- a/gnu/packages/aux-files/run-in-namespace.c
+++ b/gnu/packages/aux-files/run-in-namespace.c
@@ -620,7 +620,7 @@ main (int argc, char *argv[])
   /* SELF is something like "/home/ludo/.local/gnu/store/…-foo/bin/ls" and we
      want to extract "/home/ludo/.local/gnu/store".  */
   size_t index = strlen (self)
-    - strlen ("@WRAPPED_PROGRAM@") + strlen (original_store);
+    - strlen (WRAPPER_PROGRAM) + strlen (original_store);
   char *store = strdup (self);
   store[index] = '\0';
 
diff --git a/guix/scripts/pack.scm b/guix/scripts/pack.scm
index a5a70d5162..c353f50ced 100644
--- a/guix/scripts/pack.scm
+++ b/guix/scripts/pack.scm
@@ -856,6 +856,7 @@ last resort for relocation."
               (mkdir-p (dirname result))
               (apply invoke #$compiler "-std=gnu99" "-static" "-Os" "-g0" "-Wall"
                      "run.c" "-o" result
+                     (string-append "-DWRAPPER_PROGRAM=\"" result "\"")
                      (append (if proot
                                  (list (string-append "-DPROOT_PROGRAM=\""
                                                       proot "\""))