diff --git a/changes/not_bug_8093 b/changes/not_bug_8093
new file mode 100644
index 0000000000..98b4219268
--- /dev/null
+++ b/changes/not_bug_8093
@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - When rejecting DATA cells for stream_id zero, still count them against
+      the circuit's deliver window so that we don't get fail to send a
+      SENDME.  Fix for bug 11246; bugfix on 0.2.4.10-alpha.
diff --git a/src/or/relay.c b/src/or/relay.c
index 509d7ced04..66d1251eb7 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -1437,7 +1437,6 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
     switch (rh.command) {
       case RELAY_COMMAND_BEGIN:
       case RELAY_COMMAND_CONNECTED:
-      case RELAY_COMMAND_DATA:
       case RELAY_COMMAND_END:
       case RELAY_COMMAND_RESOLVE:
       case RELAY_COMMAND_RESOLVED:
@@ -1462,6 +1461,9 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
        * EXIT_CONN_STATE_CONNECTING or EXIT_CONN_STATE_RESOLVING.
        * This speeds up HTTP, for example. */
       optimistic_data = 1;
+    } else if (rh.stream_id == 0 && rh.command == RELAY_COMMAND_DATA) {
+      log_warn(LD_BUG, "Somehow I had a connection that matched a "
+               "data cell with stream ID 0.");
     } else {
       return connection_edge_process_relay_cell_not_open(
                &rh, cell, circ, conn, layer_hint);
@@ -1522,7 +1524,11 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
 
       circuit_consider_sending_sendme(circ, layer_hint);
 
-      if (!conn) {
+      if (rh.stream_id == 0) {
+        log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay data cell with zero "
+               "stream_id. Dropping.");
+        return 0;
+      } else if (!conn) {
         log_info(domain,"data cell dropped, unknown stream (streamid %d).",
                  rh.stream_id);
         return 0;