diff --git a/configure.ac b/configure.ac
index 31a38818..c5a351b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -119,6 +119,11 @@ AC_ARG_WITH([spdylay],
                     [Use spdylay [default=check]])],
     [request_spdylay=$withval], [request_spdylay=check])
 
+AC_ARG_WITH([mruby],
+    [AS_HELP_STRING([--with-mruby],
+                    [Use mruby [default=check]])],
+    [request_mruby=$withval], [request_mruby=check])
+
 AC_ARG_WITH([cython],
     [AS_HELP_STRING([--with-cython=PATH],
                     [Use cython in given PATH])],
@@ -370,6 +375,30 @@ fi
 
 AM_CONDITIONAL([HAVE_SPDYLAY], [ test "x${have_spdylay}" = "xyes" ])
 
+# mruby (for src/nghttpx)
+LIBS_OLD=$LIBS
+have_mruby=no
+if test "x${request_mruby}" != "xno"; then
+  AC_CHECK_LIB([mruby], [mrb_open], [have_mruby=yes], [have_mruby=no])
+  if test "x${have_mruby}" = "xyes"; then
+    AC_CHECK_HEADER([mruby.h], [have_mruby=yes], [have_mruby=no])
+    if test "x${have_mruby}" = "xyes"; then
+      LIBMRUBY_LIBS=-lmruby
+      LIBMRUBY_CFLAGS=
+      AC_SUBST([LIBMRUBY_LIBS])
+      AC_SUBST([LIBMRUBY_CFLAGS])
+    fi
+  fi
+fi
+LIBS=$LIBS_OLD
+
+if test "x${request_mruby}" = "xyes" &&
+   test "x${have_mruby}" != "xyes"; then
+  AC_MSG_ERROR([mruby was requested (--with-mruby) but not found])
+fi
+
+AM_CONDITIONAL([HAVE_MRUBY], [test "x${have_mruby}" = "xyes"])
+
 # Check Boost Asio library
 have_asio_lib=no
 
@@ -717,6 +746,7 @@ AC_MSG_NOTICE([summary of build options:
       Libev:          ${have_libev}
       Libevent(SSL):  ${have_libevent_openssl}
       Spdylay:        ${have_spdylay}
+      MRuby:          ${have_mruby}
       Jansson:        ${have_jansson}
       Jemalloc:       ${have_jemalloc}
       Zlib:           ${have_zlib}
diff --git a/src/Makefile.am b/src/Makefile.am
index 0384a997..52f50491 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -124,21 +124,26 @@ NGHTTPX_SRCS = \
 	shrpx_memcached_connection.cc shrpx_memcached_connection.h \
 	shrpx_memcached_request.h \
 	shrpx_memcached_result.h \
-	shrpx_mruby.cc shrpx_mruby.h \
-	shrpx_mruby_module.cc shrpx_mruby_module.h \
-	shrpx_mruby_module_request.cc shrpx_mruby_module_request.h \
-	shrpx_mruby_module_response.cc shrpx_mruby_module_response.h \
 	buffer.h memchunk.h template.h
 
 if HAVE_SPDYLAY
 NGHTTPX_SRCS += shrpx_spdy_upstream.cc shrpx_spdy_upstream.h
 endif # HAVE_SPDYLAY
 
+if HAVE_MRUBY
+NGHTTPX_SRCS += \
+	shrpx_mruby.cc shrpx_mruby.h \
+	shrpx_mruby_module.cc shrpx_mruby_module.h \
+	shrpx_mruby_module_request.cc shrpx_mruby_module_request.h \
+	shrpx_mruby_module_response.cc shrpx_mruby_module_response.h
+endif # HAVE_MRUBY
+
 noinst_LIBRARIES = libnghttpx.a
 libnghttpx_a_SOURCES = ${NGHTTPX_SRCS}
 
 nghttpx_SOURCES = shrpx.cc shrpx.h
-nghttpx_LDADD = libnghttpx.a ${LDADD} -lmruby
+nghttpx_CPPFLAGS = ${AM_CPPFLAGS} @LIBMRUBY_CFLAGS@
+nghttpx_LDADD = libnghttpx.a ${LDADD} @LIBMRUBY_LIBS@
 
 if HAVE_CUNIT
 check_PROGRAMS += nghttpx-unittest
@@ -152,9 +157,10 @@ nghttpx_unittest_SOURCES = shrpx-unittest.cc \
 	nghttp2_gzip.c nghttp2_gzip.h \
 	buffer_test.cc buffer_test.h \
 	memchunk_test.cc memchunk_test.h
-nghttpx_unittest_CPPFLAGS = ${AM_CPPFLAGS}\
+nghttpx_unittest_CPPFLAGS = ${AM_CPPFLAGS} @LIBMRUBY_CFLAGS@ \
 	-DNGHTTP2_TESTS_DIR=\"$(top_srcdir)/tests\"
-nghttpx_unittest_LDADD = libnghttpx.a ${LDADD} -lmruby @CUNIT_LIBS@ @TESTLDADD@
+nghttpx_unittest_LDADD = libnghttpx.a ${LDADD} \
+	@LIBMRUBY_LIBS@ @CUNIT_LIBS@ @TESTLDADD@
 
 TESTS += nghttpx-unittest
 endif # HAVE_CUNIT
diff --git a/src/shrpx_connection_handler.cc b/src/shrpx_connection_handler.cc
index 0dc6dcb3..8b82db5f 100644
--- a/src/shrpx_connection_handler.cc
+++ b/src/shrpx_connection_handler.cc
@@ -160,9 +160,11 @@ int ConnectionHandler::create_single_worker() {
 
   single_worker_ = make_unique<Worker>(loop_, sv_ssl_ctx, cl_ssl_ctx, cert_tree,
                                        ticket_keys_);
+#ifdef HAVE_MRUBY
   if (single_worker_->create_mruby_context() != 0) {
     return -1;
   }
+#endif // HAVE_MRUBY
 
   return 0;
 }
@@ -184,9 +186,11 @@ int ConnectionHandler::create_worker_thread(size_t num) {
 
     auto worker = make_unique<Worker>(loop, sv_ssl_ctx, cl_ssl_ctx, cert_tree,
                                       ticket_keys_);
+#ifdef HAVE_MRUBY
     if (worker->create_mruby_context() != 0) {
       return -1;
     }
+#endif // HAVE_MRUBY
 
     workers_.push_back(std::move(worker));
 
diff --git a/src/shrpx_http2_upstream.cc b/src/shrpx_http2_upstream.cc
index 5a0e075e..ed26e207 100644
--- a/src/shrpx_http2_upstream.cc
+++ b/src/shrpx_http2_upstream.cc
@@ -37,7 +37,9 @@
 #include "shrpx_http.h"
 #include "shrpx_worker.h"
 #include "shrpx_http2_session.h"
+#ifdef HAVE_MRUBY
 #include "shrpx_mruby.h"
+#endif // HAVE_MRUBY
 #include "http2.h"
 #include "util.h"
 #include "base64.h"
@@ -318,6 +320,7 @@ int Http2Upstream::on_request_headers(Downstream *downstream,
 
   downstream->set_request_state(Downstream::HEADER_COMPLETE);
 
+#ifdef HAVE_MRUBY
   auto upstream = downstream->get_upstream();
   auto handler = upstream->get_client_handler();
   auto worker = handler->get_worker();
@@ -329,6 +332,7 @@ int Http2Upstream::on_request_headers(Downstream *downstream,
     }
     return 0;
   }
+#endif // HAVE_MRUBY
 
   if (frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
     downstream->disable_upstream_rtimer();
@@ -1271,6 +1275,7 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream) {
         downstream->get_request_http2_scheme());
   }
 
+#ifdef HAVE_MRUBY
   if (!downstream->get_non_final_response()) {
     auto worker = handler_->get_worker();
     auto mruby_ctx = worker->get_mruby_context();
@@ -1286,6 +1291,7 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream) {
       return -1;
     }
   }
+#endif // HAVE_MRUBY
 
   size_t nheader = downstream->get_response_headers().size();
   auto nva = std::vector<nghttp2_nv>();
diff --git a/src/shrpx_https_upstream.cc b/src/shrpx_https_upstream.cc
index 60d5e28f..8857c670 100644
--- a/src/shrpx_https_upstream.cc
+++ b/src/shrpx_https_upstream.cc
@@ -37,7 +37,9 @@
 #include "shrpx_log_config.h"
 #include "shrpx_worker.h"
 #include "shrpx_http2_session.h"
+#ifdef HAVE_MRUBY
 #include "shrpx_mruby.h"
+#endif // HAVE_MRUBY
 #include "http2.h"
 #include "util.h"
 #include "template.h"
@@ -328,6 +330,7 @@ int htp_hdrs_completecb(http_parser *htp) {
 
   downstream->set_request_state(Downstream::HEADER_COMPLETE);
 
+#ifdef HAVE_MRUBY
   auto handler = upstream->get_client_handler();
   auto worker = handler->get_worker();
   auto mruby_ctx = worker->get_mruby_context();
@@ -336,6 +339,7 @@ int htp_hdrs_completecb(http_parser *htp) {
     downstream->set_response_http_status(500);
     return -1;
   }
+#endif // HAVE_MRUBY
 
   // mruby hook may change method value
 
@@ -888,6 +892,7 @@ int HttpsUpstream::on_downstream_header_complete(Downstream *downstream) {
     }
   }
 
+#ifdef HAVE_MRUBY
   if (!downstream->get_non_final_response()) {
     auto worker = handler_->get_worker();
     auto mruby_ctx = worker->get_mruby_context();
@@ -901,6 +906,7 @@ int HttpsUpstream::on_downstream_header_complete(Downstream *downstream) {
       return -1;
     }
   }
+#endif // HAVE_MRUBY
 
   auto connect_method = downstream->get_request_method() == HTTP_CONNECT;
 
diff --git a/src/shrpx_spdy_upstream.cc b/src/shrpx_spdy_upstream.cc
index 4f932431..ee66c228 100644
--- a/src/shrpx_spdy_upstream.cc
+++ b/src/shrpx_spdy_upstream.cc
@@ -36,7 +36,9 @@
 #include "shrpx_downstream_connection.h"
 #include "shrpx_config.h"
 #include "shrpx_http.h"
+#ifdef HAVE_MRUBY
 #include "shrpx_mruby.h"
+#endif // HAVE_MRUBY
 #include "shrpx_worker.h"
 #include "shrpx_http2_session.h"
 #include "http2.h"
@@ -243,6 +245,7 @@ void on_ctrl_recv_callback(spdylay_session *session, spdylay_frame_type type,
 
     downstream->set_request_state(Downstream::HEADER_COMPLETE);
 
+#ifdef HAVE_MRUBY
     auto handler = upstream->get_client_handler();
     auto worker = handler->get_worker();
     auto mruby_ctx = worker->get_mruby_context();
@@ -254,6 +257,7 @@ void on_ctrl_recv_callback(spdylay_session *session, spdylay_frame_type type,
       }
       return;
     }
+#endif // HAVE_MRUBY
 
     if (frame->syn_stream.hd.flags & SPDYLAY_CTRL_FLAG_FIN) {
       if (!downstream->validate_request_bodylen()) {
@@ -930,6 +934,7 @@ int SpdyUpstream::on_downstream_header_complete(Downstream *downstream) {
     return 0;
   }
 
+#ifdef HAVE_MRUBY
   auto worker = handler_->get_worker();
   auto mruby_ctx = worker->get_mruby_context();
 
@@ -943,6 +948,7 @@ int SpdyUpstream::on_downstream_header_complete(Downstream *downstream) {
   if (downstream->get_response_state() == Downstream::MSG_COMPLETE) {
     return -1;
   }
+#endif // HAVE_MRUBY
 
   if (LOG_ENABLED(INFO)) {
     DLOG(INFO, downstream) << "HTTP response header completed";
diff --git a/src/shrpx_worker.cc b/src/shrpx_worker.cc
index 006e7e3a..fadd6494 100644
--- a/src/shrpx_worker.cc
+++ b/src/shrpx_worker.cc
@@ -37,7 +37,9 @@
 #include "shrpx_log_config.h"
 #include "shrpx_connect_blocker.h"
 #include "shrpx_memcached_dispatcher.h"
+#ifdef HAVE_MRUBY
 #include "shrpx_mruby.h"
+#endif // HAVE_MRUBY
 #include "util.h"
 #include "template.h"
 
@@ -266,6 +268,7 @@ MemcachedDispatcher *Worker::get_session_cache_memcached_dispatcher() {
   return session_cache_memcached_dispatcher_.get();
 }
 
+#ifdef HAVE_MRUBY
 int Worker::create_mruby_context() {
   mruby_ctx_ = mruby::create_mruby_context();
   if (!mruby_ctx_) {
@@ -278,5 +281,6 @@ int Worker::create_mruby_context() {
 mruby::MRubyContext *Worker::get_mruby_context() const {
   return mruby_ctx_.get();
 }
+#endif // HAVE_MRUBY
 
 } // namespace shrpx
diff --git a/src/shrpx_worker.h b/src/shrpx_worker.h
index 38868aab..6037683d 100644
--- a/src/shrpx_worker.h
+++ b/src/shrpx_worker.h
@@ -51,11 +51,13 @@ class Http2Session;
 class ConnectBlocker;
 class MemcachedDispatcher;
 
+#ifdef HAVE_MRUBY
 namespace mruby {
 
 class MRubyContext;
 
 } // namespace mruby
+#endif // HAVE_MRUBY
 
 namespace ssl {
 class CertLookupTree;
@@ -130,9 +132,11 @@ public:
 
   MemcachedDispatcher *get_session_cache_memcached_dispatcher();
 
+#ifdef HAVE_MRUBY
   int create_mruby_context();
 
   mruby::MRubyContext *get_mruby_context() const;
+#endif // HAVE_MRUBY
 
 private:
 #ifndef NOTHREADS
@@ -147,7 +151,9 @@ private:
   WorkerStat worker_stat_;
   std::vector<DownstreamGroup> dgrps_;
   std::unique_ptr<MemcachedDispatcher> session_cache_memcached_dispatcher_;
+#ifdef HAVE_MRUBY
   std::unique_ptr<mruby::MRubyContext> mruby_ctx_;
+#endif // HAVE_MRUBY
   struct ev_loop *loop_;
 
   // Following fields are shared across threads if