diff --git a/agent/command-ssh.c b/agent/command-ssh.c
index f378ade55..0ff70b534 100644
--- a/agent/command-ssh.c
+++ b/agent/command-ssh.c
@@ -487,6 +487,8 @@ stream_read_string (estream_t stream, unsigned int secure,
   unsigned char *buffer = NULL;
   u32 length = 0;
 
+  *string_size = 0;
+
   /* Read string length.  */
   err = stream_read_uint32 (stream, &length);
   if (err)
diff --git a/agent/command.c b/agent/command.c
index 5e955ab6d..8e5d1803a 100644
--- a/agent/command.c
+++ b/agent/command.c
@@ -1809,7 +1809,7 @@ cmd_preset_passphrase (assuan_context_t ctx, char *line)
        * limit is 480 characters. */
       size_t maxlen = 480;
 
-      rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%u", maxlen);
+      rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%zu", maxlen);
       if (!rc)
 	rc = assuan_inquire (ctx, "PASSPHRASE", &passphrase, &len, maxlen);
     }
@@ -3038,7 +3038,7 @@ pinentry_loopback(ctrl_t ctrl, const char *keyword,
   gpg_error_t rc;
   assuan_context_t ctx = ctrl->server_local->assuan_ctx;
 
-  rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%u", max_length);
+  rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%zu", max_length);
   if (rc)
     return rc;
 
diff --git a/scd/ccid-driver.c b/scd/ccid-driver.c
index 3376be0e9..478d8c6c0 100644
--- a/scd/ccid-driver.c
+++ b/scd/ccid-driver.c
@@ -2673,7 +2673,7 @@ ccid_get_atr (ccid_driver_t handle,
 
       if (msglen != 10 + 4)
         {
-          DEBUGOUT_1 ("Setting PPS failed: %d\n", msglen);
+          DEBUGOUT_1 ("Setting PPS failed: %zu\n", msglen);
           return CCID_DRIVER_ERR_CARD_IO_ERROR;
         }