diff --git a/src/shrpx_http3_upstream.cc b/src/shrpx_http3_upstream.cc
index adc71a7d..c4dbbd86 100644
--- a/src/shrpx_http3_upstream.cc
+++ b/src/shrpx_http3_upstream.cc
@@ -35,6 +35,9 @@
 #include "shrpx_quic.h"
 #include "shrpx_worker.h"
 #include "shrpx_http.h"
+#ifdef HAVE_MRUBY
+#  include "shrpx_mruby.h"
+#endif // HAVE_MRUBY
 #include "http3.h"
 #include "util.h"
 
diff --git a/src/shrpx_http3_upstream.h b/src/shrpx_http3_upstream.h
index 05933a14..72816f9a 100644
--- a/src/shrpx_http3_upstream.h
+++ b/src/shrpx_http3_upstream.h
@@ -32,7 +32,6 @@
 
 #include "shrpx_upstream.h"
 #include "shrpx_downstream_queue.h"
-#include "shrpx_mruby.h"
 #include "quic.h"
 #include "network.h"