diff --git a/Documentation/git.txt b/Documentation/git.txt
index c4024d0edd9..1a6ba878232 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -12,6 +12,7 @@ SYNOPSIS
 'git' [--version] [--exec-path[=GIT_EXEC_PATH]] [--html-path]
     [-p|--paginate|--no-pager] [--no-replace-objects]
     [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]
+    [-c name=value]
     [--help] COMMAND [ARGS]
 
 DESCRIPTION
@@ -228,6 +229,12 @@ displayed. See linkgit:git-help[1] for more information,
 because `git --help ...` is converted internally into `git
 help ...`.
 
+-c <name>=<value>::
+	Pass a configuration parameter to the command. The value
+	given will override values from configuration files.
+	The <name> is expected in the same format as listed by
+	'git config' (subkeys separated by dots).
+
 --exec-path::
 	Path to wherever your core git programs are installed.
 	This can also be controlled by setting the GIT_EXEC_PATH
diff --git a/builtin/config.c b/builtin/config.c
index 4bc46b15fde..f3d1660d023 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -197,7 +197,11 @@ static int get_value(const char *key_, const char *regex_)
 		git_config_from_file(show_config, system_wide, NULL);
 	if (do_all && global)
 		git_config_from_file(show_config, global, NULL);
-	git_config_from_file(show_config, local, NULL);
+	if (do_all)
+		git_config_from_file(show_config, local, NULL);
+	git_config_from_parameters(show_config, NULL);
+	if (!do_all && !seen)
+		git_config_from_file(show_config, local, NULL);
 	if (!do_all && !seen && global)
 		git_config_from_file(show_config, global, NULL);
 	if (!do_all && !seen && system_wide)
diff --git a/cache.h b/cache.h
index 0f4263c09af..8270390c885 100644
--- a/cache.h
+++ b/cache.h
@@ -938,6 +938,8 @@ extern int update_server_info(int);
 typedef int (*config_fn_t)(const char *, const char *, void *);
 extern int git_default_config(const char *, const char *, void *);
 extern int git_config_from_file(config_fn_t fn, const char *, void *);
+extern int git_config_parse_parameter(const char *text);
+extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern int git_config(config_fn_t fn, void *);
 extern int git_parse_ulong(const char *, unsigned long *);
 extern int git_config_int(const char *, const char *);
diff --git a/config.c b/config.c
index 64e41bea224..aab53298a1a 100644
--- a/config.c
+++ b/config.c
@@ -7,6 +7,7 @@
  */
 #include "cache.h"
 #include "exec_cmd.h"
+#include "strbuf.h"
 
 #define MAXNAME (256)
 
@@ -18,6 +19,48 @@ static int zlib_compression_seen;
 
 const char *config_exclusive_filename = NULL;
 
+struct config_item
+{
+	struct config_item *next;
+	char *name;
+	char *value;
+};
+static struct config_item *config_parameters;
+static struct config_item **config_parameters_tail = &config_parameters;
+
+static void lowercase(char *p)
+{
+	for (; *p; p++)
+		*p = tolower(*p);
+}
+
+int git_config_parse_parameter(const char *text)
+{
+	struct config_item *ct;
+	struct strbuf tmp = STRBUF_INIT;
+	struct strbuf **pair;
+	strbuf_addstr(&tmp, text);
+	pair = strbuf_split(&tmp, '=');
+	if (pair[0]->len && pair[0]->buf[pair[0]->len - 1] == '=')
+		strbuf_setlen(pair[0], pair[0]->len - 1);
+	strbuf_trim(pair[0]);
+	if (!pair[0]->len) {
+		strbuf_list_free(pair);
+		return -1;
+	}
+	ct = xcalloc(1, sizeof(struct config_item));
+	ct->name = strbuf_detach(pair[0], NULL);
+	if (pair[1]) {
+		strbuf_trim(pair[1]);
+		ct->value = strbuf_detach(pair[1], NULL);
+	}
+	strbuf_list_free(pair);
+	lowercase(ct->name);
+	*config_parameters_tail = ct;
+	config_parameters_tail = &ct->next;
+	return 0;
+}
+
 static int get_next_char(void)
 {
 	int c;
@@ -712,6 +755,15 @@ int git_config_global(void)
 	return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 }
 
+int git_config_from_parameters(config_fn_t fn, void *data)
+{
+	const struct config_item *ct;
+	for (ct = config_parameters; ct; ct = ct->next)
+		if (fn(ct->name, ct->value, data) < 0)
+			return -1;
+	return 0;
+}
+
 int git_config(config_fn_t fn, void *data)
 {
 	int ret = 0, found = 0;
@@ -743,6 +795,12 @@ int git_config(config_fn_t fn, void *data)
 		found += 1;
 	}
 	free(repo_config);
+
+	if (config_parameters) {
+		ret += git_config_from_parameters(fn, data);
+		found += 1;
+	}
+
 	if (found == 0)
 		return -1;
 	return ret;
diff --git a/git.c b/git.c
index 6bae30545b8..99f036302a7 100644
--- a/git.c
+++ b/git.c
@@ -8,6 +8,7 @@ const char git_usage_string[] =
 	"git [--version] [--exec-path[=GIT_EXEC_PATH]] [--html-path]\n"
 	"           [-p|--paginate|--no-pager] [--no-replace-objects]\n"
 	"           [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]\n"
+	"           [-c name=value\n"
 	"           [--help] COMMAND [ARGS]";
 
 const char git_more_info_string[] =
@@ -130,6 +131,14 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
 			if (envchanged)
 				*envchanged = 1;
+		} else if (!strcmp(cmd, "-c")) {
+			if (*argc < 2) {
+				fprintf(stderr, "-c expects a configuration string\n" );
+				usage(git_usage_string);
+			}
+			git_config_parse_parameter((*argv)[1]);
+			(*argv)++;
+			(*argc)--;
 		} else {
 			fprintf(stderr, "Unknown option: %s\n", cmd);
 			usage(git_usage_string);
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index f11f98c3ce7..64f05080b65 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -824,4 +824,12 @@ test_expect_success 'check split_cmdline return' "
 	test_must_fail git merge master
 	"
 
+test_expect_success 'git -c "key=value" support' '
+	test "z$(git -c name=value config name)" = zvalue &&
+	test "z$(git -c core.name=value config core.name)" = zvalue &&
+	test "z$(git -c CamelCase=value config camelcase)" = zvalue &&
+	test "z$(git -c flag config --bool flag)" = ztrue &&
+	test_must_fail git -c core.name=value config name
+'
+
 test_done