diff -urN nghttp2-1.51.0-flx2.2.dist/configure.ac nghttp2-1.51.0-flx2.2/configure.ac
--- nghttp2-1.51.0-flx2.2.dist/configure.ac	2022-11-13 07:53:06.000000000 +0100
+++ nghttp2-1.51.0-flx2.2/configure.ac	2024-04-21 18:34:26.461932282 +0200
@@ -789,7 +789,7 @@
    test "x${have_zlib}" = "xyes" &&
    test "x${have_openssl}" = "xyes" &&
    test "x${have_libev}" = "xyes" &&
-   test "x${have_libcares}" = "xyes"; then
+   test "xyes" = "xyes"; then
   enable_app=yes
 fi
 
diff -urN nghttp2-1.51.0-flx2.2.dist/src/Makefile.am nghttp2-1.51.0-flx2.2/src/Makefile.am
--- nghttp2-1.51.0-flx2.2.dist/src/Makefile.am	2022-11-13 07:53:06.000000000 +0100
+++ nghttp2-1.51.0-flx2.2/src/Makefile.am	2024-04-21 18:33:13.095984808 +0200
@@ -78,7 +78,7 @@
 
 if ENABLE_APP
 
-bin_PROGRAMS += nghttp nghttpd nghttpx
+bin_PROGRAMS += nghttp nghttpd
 
 HELPER_OBJECTS = util.cc \
 	http2.cc timegm.c app_helper.cc nghttp2_gzip.c
@@ -185,61 +185,6 @@
 	quic.cc quic.h
 endif # ENABLE_HTTP3
 
-noinst_LIBRARIES = libnghttpx.a
-libnghttpx_a_SOURCES = ${NGHTTPX_SRCS}
-libnghttpx_a_CPPFLAGS = ${AM_CPPFLAGS}
-
-nghttpx_SOURCES = shrpx.cc shrpx.h
-nghttpx_CPPFLAGS = ${libnghttpx_a_CPPFLAGS}
-nghttpx_LDADD = libnghttpx.a ${LDADD}
-
-if HAVE_MRUBY
-libnghttpx_a_CPPFLAGS += \
-	-I${top_srcdir}/third-party/mruby/include @LIBMRUBY_CFLAGS@
-nghttpx_LDADD += -L${top_builddir}/third-party/mruby/build/lib @LIBMRUBY_LIBS@
-endif # HAVE_MRUBY
-
-if HAVE_NEVERBLEED
-libnghttpx_a_CPPFLAGS += -I${top_srcdir}/third-party/neverbleed
-nghttpx_LDADD += ${top_builddir}/third-party/libneverbleed.la
-endif # HAVE_NEVERBLEED
-
-if HAVE_CUNIT
-check_PROGRAMS += nghttpx-unittest
-nghttpx_unittest_SOURCES = shrpx-unittest.cc \
-	shrpx_tls_test.cc shrpx_tls_test.h \
-	shrpx_downstream_test.cc shrpx_downstream_test.h \
-	shrpx_config_test.cc shrpx_config_test.h \
-	shrpx_worker_test.cc shrpx_worker_test.h \
-	shrpx_http_test.cc shrpx_http_test.h \
-	shrpx_router_test.cc shrpx_router_test.h \
-	http2_test.cc http2_test.h \
-	util_test.cc util_test.h \
-	nghttp2_gzip_test.c nghttp2_gzip_test.h \
-	nghttp2_gzip.c nghttp2_gzip.h \
-	buffer_test.cc buffer_test.h \
-	memchunk_test.cc memchunk_test.h \
-	template_test.cc template_test.h \
-	base64_test.cc base64_test.h
-nghttpx_unittest_CPPFLAGS = ${AM_CPPFLAGS} \
-	-DNGHTTP2_SRC_DIR=\"$(top_srcdir)/src\"
-nghttpx_unittest_LDADD = libnghttpx.a ${LDADD} @CUNIT_LIBS@ @TESTLDADD@
-
-if HAVE_MRUBY
-nghttpx_unittest_CPPFLAGS += \
-	-I${top_srcdir}/third-party/mruby/include @LIBMRUBY_CFLAGS@
-nghttpx_unittest_LDADD += \
-	-L${top_builddir}/third-party/mruby/build/lib @LIBMRUBY_LIBS@
-endif # HAVE_MRUBY
-
-if HAVE_NEVERBLEED
-nghttpx_unittest_CPPFLAGS += -I${top_srcdir}/third-party/neverbleed
-nghttpx_unittest_LDADD += ${top_builddir}/third-party/libneverbleed.la
-endif # HAVE_NEVERBLEED
-
-TESTS += nghttpx-unittest
-endif # HAVE_CUNIT
-
 endif # ENABLE_APP
 
 if ENABLE_HPACK_TOOLS