diff --git a/rest_api/config.py b/rest_api/config.py
index 56e1e7675..b974fa88f 100644
--- a/rest_api/config.py
+++ b/rest_api/config.py
@@ -8,3 +8,5 @@ FILE_UPLOAD_PATH = os.getenv("FILE_UPLOAD_PATH", "./file-upload")
 
 LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO")
 ROOT_PATH = os.getenv("ROOT_PATH", "/")
+
+CONCURRENT_REQUEST_PER_WORKER = os.getenv("CONCURRENT_REQUEST_PER_WORKER", 4)
diff --git a/rest_api/controller/search.py b/rest_api/controller/search.py
index e2034310b..54425eca7 100644
--- a/rest_api/controller/search.py
+++ b/rest_api/controller/search.py
@@ -8,7 +8,7 @@ from fastapi import APIRouter
 from pydantic import BaseModel
 
 from haystack import Pipeline
-from rest_api.config import PIPELINE_YAML_PATH, LOG_LEVEL, QUERY_PIPELINE_NAME
+from rest_api.config import PIPELINE_YAML_PATH, LOG_LEVEL, QUERY_PIPELINE_NAME, CONCURRENT_REQUEST_PER_WORKER
 from rest_api.controller.utils import RequestLimiter
 
 logging.getLogger("haystack").setLevel(LOG_LEVEL)
@@ -46,7 +46,7 @@ class Response(BaseModel):
 
 PIPELINE = Pipeline.load_from_yaml(Path(PIPELINE_YAML_PATH), pipeline_name=QUERY_PIPELINE_NAME)
 logger.info(f"Loaded pipeline nodes: {PIPELINE.graph.nodes.keys()}")
-concurrency_limiter = RequestLimiter(4)
+concurrency_limiter = RequestLimiter(CONCURRENT_REQUEST_PER_WORKER)
 
 
 @router.post("/query", response_model=Response)