diff --git a/api/Dockerfile b/api/Dockerfile
index c98dadd25..7892a1eaa 100644
--- a/api/Dockerfile
+++ b/api/Dockerfile
@@ -31,7 +31,7 @@ RUN git clone --depth=1 --recurse-submodules -b $NGHTTP3_VERSION https://github.
 FROM build-dependencies AS ngtcp2
 COPY --from=openssl /usr/local/ /usr/local/
 COPY --from=nghttp3 /usr/local/ /usr/local/
-ARG NGTCP2_VERSION=v1.4.0
+ARG NGTCP2_VERSION=v1.5.0
 RUN git clone --depth=1 --recurse-submodules -b $NGTCP2_VERSION https://github.com/ngtcp2/ngtcp2 && \
     cd ngtcp2 && \
     autoreconf -fi && \