diff --git a/Dockerfile.template b/Dockerfile.template
index bbad45d..c33cc3b 100644
--- a/Dockerfile.template
+++ b/Dockerfile.template
@@ -109,8 +109,8 @@ RUN mkdir boringssl/build/lib && \
     cp -R boringssl/include boringssl/build
 {{/chrome}}
 
-ARG NGHTTP2_VERSION=nghttp2-1.46.0
-ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+ARG NGHTTP2_VERSION=nghttp2-1.56.0
+ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 
 # Download nghttp2 for HTTP/2.0 support.
 RUN curl -o ${NGHTTP2_VERSION}.tar.bz2 -L ${NGHTTP2_URL}
diff --git a/Makefile.in b/Makefile.in
index 9f9911e..712eaeb 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -14,8 +14,8 @@ NSS_VERSION := nss-3.87
 NSS_URL := https://ftp.mozilla.org/pub/security/nss/releases/NSS_3_87_RTM/src/nss-3.87-with-nspr-4.35.tar.gz
  # In case this is changed, update build-and-test-make.yml as well
 BORING_SSL_COMMIT := 3a667d10e94186fd503966f5638e134fe9fb4080
-NGHTTP2_VERSION := nghttp2-1.46.0
-NGHTTP2_URL := https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+NGHTTP2_VERSION := nghttp2-1.56.0
+NGHTTP2_URL := https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 CURL_VERSION := curl-8.1.1
 
 brotli_install_dir := $(abspath brotli-$(BROTLI_VERSION)/out/installed)
@@ -427,7 +427,7 @@ $(CURL_VERSION)/.chrome: $(chrome_libs)	$(CURL_VERSION).tar.xz $(CURL_VERSION)/.
 
 	echo "Configuring curl with: $$config_flags"
 
-	./configure $$config_flags LIBS="$$add_libs"
+	./configure $$config_flags CFLAGS="-g -ggdb" LIBS="$$add_libs"
 
 	# Remove possible leftovers from a previous compilation
 	$(MAKE) clean MAKEFLAGS=
diff --git a/chrome/Dockerfile b/chrome/Dockerfile
index ace12b4..7c749ed 100644
--- a/chrome/Dockerfile
+++ b/chrome/Dockerfile
@@ -54,8 +54,8 @@ RUN mkdir boringssl/build/lib && \
     ln -s ../ssl/libssl.a boringssl/build/lib/libssl.a && \
     cp -R boringssl/include boringssl/build
 
-ARG NGHTTP2_VERSION=nghttp2-1.46.0
-ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+ARG NGHTTP2_VERSION=nghttp2-1.56.0
+ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 
 # Download nghttp2 for HTTP/2.0 support.
 RUN curl -o ${NGHTTP2_VERSION}.tar.bz2 -L ${NGHTTP2_URL}
diff --git a/chrome/Dockerfile.alpine b/chrome/Dockerfile.alpine
index 64ae8b3..652b6db 100644
--- a/chrome/Dockerfile.alpine
+++ b/chrome/Dockerfile.alpine
@@ -51,8 +51,8 @@ RUN mkdir boringssl/build/lib && \
     ln -s ../ssl/libssl.a boringssl/build/lib/libssl.a && \
     cp -R boringssl/include boringssl/build
 
-ARG NGHTTP2_VERSION=nghttp2-1.46.0
-ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+ARG NGHTTP2_VERSION=nghttp2-1.56.0
+ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 
 # Download nghttp2 for HTTP/2.0 support.
 RUN curl -o ${NGHTTP2_VERSION}.tar.bz2 -L ${NGHTTP2_URL}
diff --git a/firefox/Dockerfile b/firefox/Dockerfile
index 8dab726..4f50042 100644
--- a/firefox/Dockerfile
+++ b/firefox/Dockerfile
@@ -50,8 +50,8 @@ RUN tar xf ${NSS_VERSION}.tar.gz && \
     cd ${NSS_VERSION}/nss && \
     ./build.sh -o --disable-tests --static --python=python3
 
-ARG NGHTTP2_VERSION=nghttp2-1.46.0
-ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+ARG NGHTTP2_VERSION=nghttp2-1.56.0
+ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 
 # Download nghttp2 for HTTP/2.0 support.
 RUN curl -o ${NGHTTP2_VERSION}.tar.bz2 -L ${NGHTTP2_URL}
diff --git a/firefox/Dockerfile.alpine b/firefox/Dockerfile.alpine
index e6b051a..9804617 100644
--- a/firefox/Dockerfile.alpine
+++ b/firefox/Dockerfile.alpine
@@ -43,8 +43,8 @@ RUN tar xf ${NSS_VERSION}.tar.gz && \
     cd ${NSS_VERSION}/nss && \
     ./build.sh -o --disable-tests --static --python=python3
 
-ARG NGHTTP2_VERSION=nghttp2-1.46.0
-ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+ARG NGHTTP2_VERSION=nghttp2-1.56.0
+ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 
 # Download nghttp2 for HTTP/2.0 support.
 RUN curl -o ${NGHTTP2_VERSION}.tar.bz2 -L ${NGHTTP2_URL}