diff --git a/src/httpcore2/httpcore2/_async/http2.py b/src/httpcore2/httpcore2/_async/http2.py
index ae3e764c..156b3ea0 100644
--- a/src/httpcore2/httpcore2/_async/http2.py
+++ b/src/httpcore2/httpcore2/_async/http2.py
@@ -123,6 +123,7 @@ async def handle_async_request(self, request: Request) -> Response:
         except h2.exceptions.NoAvailableStreamIDError:  # pragma: no cover
             self._used_all_stream_ids = True
             self._request_count -= 1
+            await self._max_streams_semaphore.release()
             raise ConnectionNotAvailable()
 
         try:
diff --git a/src/httpcore2/httpcore2/_sync/http2.py b/src/httpcore2/httpcore2/_sync/http2.py
index 0512c4a2..ca3fc215 100644
--- a/src/httpcore2/httpcore2/_sync/http2.py
+++ b/src/httpcore2/httpcore2/_sync/http2.py
@@ -123,6 +123,7 @@ def handle_request(self, request: Request) -> Response:
         except h2.exceptions.NoAvailableStreamIDError:  # pragma: no cover
             self._used_all_stream_ids = True
             self._request_count -= 1
+            self._max_streams_semaphore.release()
             raise ConnectionNotAvailable()
 
         try: