diff --git a/trezor_agent/gpg/signer.py b/trezor_agent/gpg/signer.py
index 1f787c7..7654251 100755
--- a/trezor_agent/gpg/signer.py
+++ b/trezor_agent/gpg/signer.py
@@ -2,6 +2,7 @@
 """Create signatures and export public keys for GPG using TREZOR."""
 import argparse
 import logging
+import subprocess as sp
 import sys
 import time
 
@@ -14,6 +15,14 @@ def _open_output(filename):
     return sys.stdout if filename == '-' else open(filename, 'wb')
 
 
+def _call_with_input(args, blob):
+    p = sp.Popen(args=args, stdin=sp.PIPE)
+    p.stdin.write(blob)
+    p.stdin.close()
+    exit_code = p.wait()
+    assert exit_code == 0, exit_code
+
+
 def main():
     """Main function."""
     p = argparse.ArgumentParser()
@@ -23,7 +32,10 @@ def main():
     p.add_argument('-a', '--armor', action='store_true', default=False)
     p.add_argument('-v', '--verbose', action='store_true', default=False)
     p.add_argument('-e', '--ecdsa-curve', default='nist256p1')
-    p.add_argument('-o', '--output-file')
+    p.add_argument('-o', '--output',
+                   help='Output file name for the results. '
+                   'Use "-" to write the results to stdout or "GPG" '
+                   'to import a public key into the local keyring.')
 
     args = p.parse_args()
     logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO,
@@ -37,9 +49,12 @@ def main():
         if args.armor:
             pubkey = encode.armor(pubkey, 'PUBLIC KEY BLOCK')
             ext = '.asc'
-        filename = args.output_file or (s.hex_short_key_id() + ext)
-        _open_output(filename).write(pubkey)
-        log.info('import to local keyring using "gpg2 --import %s"', filename)
+        filename = args.output or (s.hex_short_key_id() + ext)
+        if filename == 'GPG':
+            log.info('importing public key to local keyring')
+            _call_with_input(['gpg2', '--import'], pubkey)
+        else:
+            _open_output(filename).write(pubkey)
     else:
         pubkey = decode.load_from_gpg(user_id)
         s = encode.Signer.from_public_key(pubkey=pubkey, user_id=user_id)
@@ -48,7 +63,7 @@ def main():
         if args.armor:
             sig = encode.armor(sig, 'SIGNATURE')
             ext = '.asc'
-        filename = args.output_file or (args.filename + ext)
+        filename = args.output or (args.filename + ext)
         _open_output(filename).write(sig)
         check.verify(pubkey=pubkey, sig_file=filename)