diff --git a/meta-signing-key/classes/user-key-store.bbclass b/meta-signing-key/classes/user-key-store.bbclass
index 55876d0..960bde6 100644
--- a/meta-signing-key/classes/user-key-store.bbclass
+++ b/meta-signing-key/classes/user-key-store.bbclass
@@ -536,6 +536,10 @@ def boot_sign(input, d):
     status, output = oe.utils.getstatusoutput(cmd)
     if status:
         bb.fatal('Failed to sign: %s' % (input))
+    gpg_conf = bb.utils.which(os.getenv('PATH'), 'gpgconf')
+    cmd = 'GNUPGHOME=%s %s --kill gpg-agent' % \
+            (gpg_path, gpg_conf)
+    status, output = oe.utils.getstatusoutput(cmd)
 
 def uks_boot_sign(input, d):
     boot_sign(input, d)