diff --git a/Documentation/config.txt b/Documentation/config.txt
index 1cc18a828c..ac373e3f48 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1828,6 +1828,10 @@ gpg.program::
 	signed, and the program is expected to send the result to its
 	standard output.
 
+gpg.format::
+	Specifies which key format to use when signing with `--gpg-sign`.
+	Default is "openpgp", that is also the only supported value.
+
 gui.commitMsgWidth::
 	Defines how wide the commit message window is in the
 	linkgit:git-gui[1]. "75" is the default.
diff --git a/gpg-interface.c b/gpg-interface.c
index 09ddfbc267..b39a27980b 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -7,6 +7,7 @@
 #include "tempfile.h"
 
 static char *configured_signing_key;
+static const char *gpg_format = "openpgp";
 static const char *gpg_program = "gpg";
 
 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
@@ -138,6 +139,15 @@ int git_gpg_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (!strcmp(var, "gpg.format")) {
+		if (!value)
+			return config_error_nonbool(var);
+		if (strcmp(value, "openpgp"))
+			return error("unsupported value for %s: %s",
+				     var, value);
+		return git_config_string(&gpg_format, var, value);
+	}
+
 	if (!strcmp(var, "gpg.program")) {
 		if (!value)
 			return config_error_nonbool(var);