diff --git a/Makefile b/Makefile
index 71339e1098..7c585e866c 100644
--- a/Makefile
+++ b/Makefile
@@ -546,6 +546,7 @@ BUILTIN_OBJS += builtin-rev-parse.o
 BUILTIN_OBJS += builtin-revert.o
 BUILTIN_OBJS += builtin-rm.o
 BUILTIN_OBJS += builtin-send-pack.o
+BUILTIN_OBJS += builtin-shell.o
 BUILTIN_OBJS += builtin-shortlog.o
 BUILTIN_OBJS += builtin-show-branch.o
 BUILTIN_OBJS += builtin-show-ref.o
@@ -821,7 +822,6 @@ EXTLIBS += -lz
 ifndef NO_POSIX_ONLY_PROGRAMS
 	PROGRAMS += git-daemon$X
 	PROGRAMS += git-imap-send$X
-	PROGRAMS += git-shell$X
 endif
 ifndef NO_OPENSSL
 	OPENSSL_LIBSSL = -lssl
diff --git a/shell.c b/builtin-shell.c
similarity index 94%
rename from shell.c
rename to builtin-shell.c
index 0f6a727a8c..3cf97d4f5d 100644
--- a/shell.c
+++ b/builtin-shell.c
@@ -2,6 +2,7 @@
 #include "quote.h"
 #include "exec_cmd.h"
 #include "strbuf.h"
+#include "builtin.h"
 
 static int do_generic_cmd(const char *me, char *arg)
 {
@@ -44,7 +45,7 @@ static struct commands {
 	{ NULL },
 };
 
-int main(int argc, char **argv)
+int cmd_shell(int argc, const char **argv, const char *prefix)
 {
 	char *prog;
 	struct commands *cmd;
@@ -62,7 +63,7 @@ int main(int argc, char **argv)
 	else if (argc != 3 || strcmp(argv[1], "-c"))
 		die("What do you think I am? A shell?");
 
-	prog = argv[2];
+	prog = xstrdup(argv[2]);
 	if (!strncmp(prog, "git", 3) && isspace(prog[3]))
 		/* Accept "git foo" as if the caller said "git-foo". */
 		prog[3] = '-';
diff --git a/builtin.h b/builtin.h
index f3502d305e..2b57a5eb6b 100644
--- a/builtin.h
+++ b/builtin.h
@@ -88,6 +88,7 @@ extern int cmd_rev_parse(int argc, const char **argv, const char *prefix);
 extern int cmd_revert(int argc, const char **argv, const char *prefix);
 extern int cmd_rm(int argc, const char **argv, const char *prefix);
 extern int cmd_send_pack(int argc, const char **argv, const char *prefix);
+extern int cmd_shell(int argc, const char **argv, const char *prefix);
 extern int cmd_shortlog(int argc, const char **argv, const char *prefix);
 extern int cmd_show(int argc, const char **argv, const char *prefix);
 extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
diff --git a/git.c b/git.c
index 37b1d76a08..89e4645736 100644
--- a/git.c
+++ b/git.c
@@ -338,6 +338,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 		{ "rm", cmd_rm, RUN_SETUP },
 		{ "send-pack", cmd_send_pack, RUN_SETUP },
+		{ "shell", cmd_shell },
 		{ "shortlog", cmd_shortlog, USE_PAGER },
 		{ "show-branch", cmd_show_branch, RUN_SETUP },
 		{ "show", cmd_show, RUN_SETUP | USE_PAGER },