diff --git a/builtin/commit.c b/builtin/commit.c
index f53e7e8..75c7411 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -113,7 +113,7 @@ static char *template_file;
  * the commit message and/or authorship.
  */
 static const char *author_message, *author_message_buffer;
-static char *edit_message, *use_message;
+static const char *edit_message, *use_message;
 static char *fixup_message, *fixup_commit, *squash_message;
 static const char *fixup_prefix;
 static int all, also, interactive, patch_interactive, only, amend, signoff;
@@ -121,8 +121,8 @@ static int edit_flag = -1; /* unspecified */
 static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
 static int config_commit_verbose = -1; /* unspecified */
 static int no_post_rewrite, allow_empty_message, pathspec_file_nul;
-static char *untracked_files_arg, *force_date, *ignore_submodule_arg, *ignored_arg;
-static char *sign_commit, *pathspec_from_file;
+static const char *untracked_files_arg, *force_date, *ignore_submodule_arg, *ignored_arg;
+static const char *sign_commit, *pathspec_from_file;
 static struct strvec trailer_args = STRVEC_INIT;
 
 /*