diff --git a/httpcore/_async/http2.py b/httpcore/_async/http2.py
index dbd0beeb..9c1482e6 100644
--- a/httpcore/_async/http2.py
+++ b/httpcore/_async/http2.py
@@ -136,6 +136,7 @@ async def handle_async_request(self, request: Request) -> Response:
         except h2.exceptions.NoAvailableStreamIDError:  # pragma: nocover
             self._used_all_stream_ids = True
             self._request_count -= 1
+            await self._max_streams_semaphore.release()
             raise ConnectionNotAvailable()
 
         try:
diff --git a/httpcore/_sync/http2.py b/httpcore/_sync/http2.py
index ddcc1890..d22e0fda 100644
--- a/httpcore/_sync/http2.py
+++ b/httpcore/_sync/http2.py
@@ -136,6 +136,7 @@ def handle_request(self, request: Request) -> Response:
         except h2.exceptions.NoAvailableStreamIDError:  # pragma: nocover
             self._used_all_stream_ids = True
             self._request_count -= 1
+            self._max_streams_semaphore.release()
             raise ConnectionNotAvailable()
 
         try: