diff --git a/moto/ecs/responses.py b/moto/ecs/responses.py
index b061fd19c..b279ee793 100644
--- a/moto/ecs/responses.py
+++ b/moto/ecs/responses.py
@@ -115,7 +115,7 @@ class EC2ContainerServiceResponse(BaseResponse):
         cluster_str = self._get_param("cluster", "default")
         overrides = self._get_param("overrides")
         task_definition_str = self._get_param("taskDefinition")
-        count = self._get_int_param("count")
+        count = self._get_int_param("count", 1)
         started_by = self._get_param("startedBy")
         tags = self._get_param("tags")
         launch_type = self._get_param("launchType")
diff --git a/tests/test_ecs/test_ecs_boto3.py b/tests/test_ecs/test_ecs_boto3.py
index ef9aec94a..6340173ae 100644
--- a/tests/test_ecs/test_ecs_boto3.py
+++ b/tests/test_ecs/test_ecs_boto3.py
@@ -1590,6 +1590,13 @@ def test_run_task():
             }
         ],
     )
+    response = client.run_task(
+        cluster="test_ecs_cluster",
+        overrides={},
+        taskDefinition="test_ecs_task",
+        startedBy="moto",
+    )
+    len(response["tasks"]).should.equal(1)
     response = client.run_task(
         cluster="test_ecs_cluster",
         overrides={},