diff --git a/cache.h b/cache.h
index ce7b386a4d..43ba6a3ba5 100644
--- a/cache.h
+++ b/cache.h
@@ -615,7 +615,7 @@ extern int pager_in_use(void);
 extern int pager_use_color;
 
 extern const char *editor_program;
-extern char *excludes_file;
+extern const char *excludes_file;
 
 /* base85 */
 int decode_85(char *dst, const char *line, int linelen);
diff --git a/config.c b/config.c
index 703c2085a5..b82907cb85 100644
--- a/config.c
+++ b/config.c
@@ -446,12 +446,8 @@ int git_default_config(const char *var, const char *value)
 	if (!strcmp(var, "core.editor"))
 		return git_config_string(&editor_program, var, value);
 
-	if (!strcmp(var, "core.excludesfile")) {
-		if (!value)
-			return config_error_nonbool(var);
-		excludes_file = xstrdup(value);
-		return 0;
-	}
+	if (!strcmp(var, "core.excludesfile"))
+		return git_config_string(&excludes_file, var, value);
 
 	if (!strcmp(var, "core.whitespace")) {
 		if (!value)
diff --git a/environment.c b/environment.c
index 9556009324..fa3633372b 100644
--- a/environment.c
+++ b/environment.c
@@ -33,7 +33,7 @@ size_t delta_base_cache_limit = 16 * 1024 * 1024;
 const char *pager_program;
 int pager_use_color = 1;
 const char *editor_program;
-char *excludes_file;
+const char *excludes_file;
 int auto_crlf = 0;	/* 1: both ways, -1: only when adding git objects */
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;