diff --git a/cache.h b/cache.h
index 2928107bb135004e11f6a11a625067545680b62a..535153e1b32e2f9c7b0644aadccd725a0613746d 100644
--- a/cache.h
+++ b/cache.h
@@ -949,6 +949,7 @@ extern int git_config_set_multivar(const char *, const char *, const char *, int
 extern int git_config_rename_section(const char *, const char *);
 extern const char *git_etc_gitconfig(void);
 extern int check_repository_format_version(const char *var, const char *value, void *cb);
+extern int git_env_bool(const char *, int);
 extern int git_config_system(void);
 extern int git_config_global(void);
 extern int config_error_nonbool(const char *);
diff --git a/config.c b/config.c
index 6963fbea43e6420f5f8dafc5b94fb5c27de6ffd2..70e460016e1bb56295686768dd0b1cc6b981881e 100644
--- a/config.c
+++ b/config.c
@@ -683,7 +683,7 @@ const char *git_etc_gitconfig(void)
 	return system_wide;
 }
 
-static int git_env_bool(const char *k, int def)
+int git_env_bool(const char *k, int def)
 {
 	const char *v = getenv(k);
 	return v ? git_config_bool(k, v) : def;