diff --git a/old-configure.in b/old-configure.in
index 510b68fe0b24..f20348bade2a 100644
--- a/old-configure.in
+++ b/old-configure.in
@@ -776,10 +776,6 @@ if test "$MOZILLA_OFFICIAL"; then
     MOZ_INCLUDE_SOURCE_INFO=1
 fi
 
-# External builds (specifically Ubuntu) may drop the hg repo information, so we allow to
-# explicitly set the repository and changeset information in.
-AC_SUBST(MOZ_SOURCE_REPO)
-AC_SUBST(MOZ_SOURCE_CHANGESET)
 AC_SUBST(MOZ_INCLUDE_SOURCE_INFO)
 
 dnl Echo the CFLAGS to remove extra whitespace.
diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index fea68ade8c05..0ac9df0ebed7 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -29,6 +29,13 @@ set_define(
     "BROWSER_CHROME_URL_QUOTED", depends_if("BROWSER_CHROME_URL")(lambda v: f'"{v[0]}"')
 )
 
+# External builds (specifically Ubuntu) may drop the hg repo information, so we allow to
+# explicitly set the repository and changeset information in.
+option(env="MOZ_SOURCE_REPO", nargs=1, help="project source repository")
+set_config("MOZ_SOURCE_REPO", depends_if("MOZ_SOURCE_REPO")(lambda src: src[0]))
+option(env="MOZ_SOURCE_CHANGESET", nargs=1, help="source changeset")
+set_config("MOZ_SOURCE_CHANGESET", depends_if("MOZ_SOURCE_CHANGESET")(lambda v: v[0]))
+
 
 # Set the MOZ_CONFIGURE_OPTIONS variable with all the options that
 # were passed somehow (environment, command line, mozconfig)