diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 1d7ed040c31..85ea5099915 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -5806,13 +5806,26 @@ static bool StreamTraceEvents(Dart_StreamConsumer consumer,
   char* output = NULL;
   intptr_t output_length = 0;
   js->Steal(const_cast<const char**>(&output), &output_length);
+  if (output_length < 3) {
+    // Empty JSON array.
+    free(output);
+    return false;
+  }
+  // We want to send the JSON array without the leading '[' or trailing ']'
+  // characters.
+  ASSERT(output[0] == '[');
+  ASSERT(output[output_length - 1] == ']');
+  // Replace the ']' with the null character.
+  output[output_length - 1] = '\0';
+  // We are skipping the '['.
+  output_length -= 1;
 
   // Start the stream.
   StartStreamToConsumer(consumer, user_data, "timeline");
 
   DataStreamToConsumer(consumer,
                        user_data,
-                       output,
+                       &output[1],
                        output_length,
                        "timeline");
 
diff --git a/runtime/vm/dart_api_impl_test.cc b/runtime/vm/dart_api_impl_test.cc
index 501091ce930..b11ffb418aa 100644
--- a/runtime/vm/dart_api_impl_test.cc
+++ b/runtime/vm/dart_api_impl_test.cc
@@ -9562,6 +9562,12 @@ TEST_CASE(Timeline_Dart_TimelineGetTrace) {
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
@@ -9609,6 +9615,12 @@ TEST_CASE(Timeline_Dart_TimelineGetTraceOnlyDartEvents) {
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Dart\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"DART_NAME\"", buffer);
@@ -9654,6 +9666,12 @@ TEST_CASE(Timeline_Dart_TimelineGetTraceWithDartEvents) {
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
@@ -9697,6 +9715,12 @@ TEST_CASE(Timeline_Dart_TimelineGetTraceGlobalOverride) {
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
@@ -9745,6 +9769,12 @@ TEST_CASE(Timeline_Dart_GlobalTimelineGetTrace) {
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"name\":\"TestVMDuration\"", buffer);
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
@@ -9779,6 +9809,11 @@ TEST_CASE(Timeline_Dart_GlobalTimelineGetTrace) {
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
 
   // Heartbeat test for old events.
   EXPECT_SUBSTRING("\"name\":\"TestVMDuration\"", buffer);