diff --git a/block/stream.c b/block/stream.c
index 0433409..34de8ba 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -32,7 +32,7 @@ typedef struct StreamBlockJob {
     RateLimit limit;
     BlockDriverState *base;
     BlockdevOnError on_error;
-    char backing_file_id[1024];
+    char *backing_file_str;
 } StreamBlockJob;
 
 static int coroutine_fn stream_populate(BlockDriverState *bs,
@@ -186,7 +186,7 @@ wait:
     if (!block_job_is_cancelled(&s->common) && sector_num == end && ret == 0) {
         const char *base_id = NULL, *base_fmt = NULL;
         if (base) {
-            base_id = s->backing_file_id;
+            base_id = s->backing_file_str;
             if (base->drv) {
                 base_fmt = base->drv->format_name;
             }
@@ -196,6 +196,7 @@ wait:
     }
 
     qemu_vfree(buf);
+    g_free(s->backing_file_str);
     block_job_completed(&s->common, ret);
 }
 
@@ -217,7 +218,7 @@ static const BlockJobDriver stream_job_driver = {
 };
 
 void stream_start(BlockDriverState *bs, BlockDriverState *base,
-                  const char *base_id, int64_t speed,
+                  const char *backing_file_str, int64_t speed,
                   BlockdevOnError on_error,
                   BlockDriverCompletionFunc *cb,
                   void *opaque, Error **errp)
@@ -237,9 +238,7 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
     }
 
     s->base = base;
-    if (base_id) {
-        pstrcpy(s->backing_file_id, sizeof(s->backing_file_id), base_id);
-    }
+    s->backing_file_str = g_strdup(backing_file_str);
 
     s->on_error = on_error;
     s->common.co = qemu_coroutine_create(stream_run);
diff --git a/blockdev.c b/blockdev.c
index 4a7885e..61b84d0 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1866,14 +1866,17 @@ static void block_job_cb(void *opaque, int ret)
     bdrv_put_ref_bh_schedule(bs);
 }
 
-void qmp_block_stream(const char *device, bool has_base,
-                      const char *base, bool has_speed, int64_t speed,
+void qmp_block_stream(const char *device,
+                      bool has_base, const char *base,
+                      bool has_backing_file, const char *backing_file,
+                      bool has_speed, int64_t speed,
                       bool has_on_error, BlockdevOnError on_error,
                       Error **errp)
 {
     BlockDriverState *bs;
     BlockDriverState *base_bs = NULL;
     Error *local_err = NULL;
+    const char *base_name = NULL;
 
     if (!has_on_error) {
         on_error = BLOCKDEV_ON_ERROR_REPORT;
@@ -1889,15 +1892,27 @@ void qmp_block_stream(const char *device, bool has_base,
         return;
     }
 
-    if (base) {
+    if (has_base) {
         base_bs = bdrv_find_backing_image(bs, base);
         if (base_bs == NULL) {
             error_set(errp, QERR_BASE_NOT_FOUND, base);
             return;
         }
+        base_name = base;
     }
 
-    stream_start(bs, base_bs, base, has_speed ? speed : 0,
+    /* if we are streaming the entire chain, the result will have no backing
+     * file, and specifying one is therefore an error */
+    if (base_bs == NULL && has_backing_file) {
+        error_setg(errp, "backing file specified, but streaming the "
+                         "entire chain");
+        return;
+    }
+
+    /* backing_file string overrides base bs filename */
+    base_name = has_backing_file ? backing_file : base_name;
+
+    stream_start(bs, base_bs, base_name, has_speed ? speed : 0,
                  on_error, block_job_cb, bs, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
diff --git a/hmp.c b/hmp.c
index dc3d279..0dc2499 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1175,7 +1175,7 @@ void hmp_block_stream(Monitor *mon, const QDict *qdict)
     const char *base = qdict_get_try_str(qdict, "base");
     int64_t speed = qdict_get_try_int(qdict, "speed", 0);
 
-    qmp_block_stream(device, base != NULL, base,
+    qmp_block_stream(device, base != NULL, base, false, NULL,
                      qdict_haskey(qdict, "speed"), speed,
                      true, BLOCKDEV_ON_ERROR_REPORT, &error);
 
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 9ebe38c..f1b505b 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -888,6 +888,21 @@
 #
 # @base:   #optional the common backing file name
 #
+# @backing-file: #optional The backing file string to write into the active
+#                          layer. This filename is not validated.
+#
+#                          If a pathname string is such that it cannot be
+#                          resolved by QEMU, that means that subsequent QMP or
+#                          HMP commands must use node-names for the image in
+#                          question, as filename lookup methods will fail.
+#
+#                          If not specified, QEMU will automatically determine
+#                          the backing file string to use, or error out if there
+#                          is no obvious choice.  Care should be taken when
+#                          specifying the string, to specify a valid filename or
+#                          protocol.
+#                          (Since 2.1)
+#
 # @speed:  #optional the maximum speed, in bytes per second
 #
 # @on-error: #optional the action to take on an error (default report).
@@ -900,8 +915,8 @@
 # Since: 1.1
 ##
 { 'command': 'block-stream',
-  'data': { 'device': 'str', '*base': 'str', '*speed': 'int',
-            '*on-error': 'BlockdevOnError' } }
+  'data': { 'device': 'str', '*base': 'str', '*backing-file': 'str',
+            '*speed': 'int', '*on-error': 'BlockdevOnError' } }
 
 ##
 # @block-job-set-speed:
diff --git a/qmp-commands.hx b/qmp-commands.hx
index e0dea3f..7b029c4 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -979,7 +979,7 @@ EQMP
 
     {
         .name       = "block-stream",
-        .args_type  = "device:B,base:s?,speed:o?,on-error:s?",
+        .args_type  = "device:B,base:s?,speed:o?,backing-file:s?,on-error:s?",
         .mhandler.cmd_new = qmp_marshal_input_block_stream,
     },
 
