diff --git a/examples/client.c b/examples/client.c
index b2680f61..b12c3e48 100644
--- a/examples/client.c
+++ b/examples/client.c
@@ -30,7 +30,7 @@
 #include <config.h>
 #endif /* HAVE_CONFIG_H */
 
-#include <stdint.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
diff --git a/lib/includes/nghttp2/nghttp2.h b/lib/includes/nghttp2/nghttp2.h
index c9857e16..4edba80e 100644
--- a/lib/includes/nghttp2/nghttp2.h
+++ b/lib/includes/nghttp2/nghttp2.h
@@ -36,7 +36,7 @@ extern "C" {
 #endif
 
 #include <stdlib.h>
-#include <stdint.h>
+#include <inttypes.h>
 #include <sys/types.h>
 
 #include <nghttp2/nghttp2ver.h>
diff --git a/src/HttpServer.h b/src/HttpServer.h
index 3d96bc22..a91e7d3c 100644
--- a/src/HttpServer.h
+++ b/src/HttpServer.h
@@ -27,9 +27,9 @@
 
 #include "nghttp2_config.h"
 
-#include <stdint.h>
 #include <sys/types.h>
 
+#include <cinttypes>
 #include <cstdlib>
 
 #include <string>
diff --git a/src/app_helper.h b/src/app_helper.h
index 14aba711..034489f4 100644
--- a/src/app_helper.h
+++ b/src/app_helper.h
@@ -27,7 +27,7 @@
 
 #include "nghttp2_config.h"
 
-#include <stdint.h>
+#include <cinttypes>
 #include <cstdlib>
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
diff --git a/src/h2load_session.h b/src/h2load_session.h
index 4231b914..18175748 100644
--- a/src/h2load_session.h
+++ b/src/h2load_session.h
@@ -28,7 +28,8 @@
 #include "nghttp2_config.h"
 
 #include <sys/types.h>
-#include <stdint.h>
+
+#include <cinttypes>
 
 #include "h2load.h"
 
diff --git a/src/shrpx.cc b/src/shrpx.cc
index 2cb2cc59..9cbcc367 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -24,7 +24,6 @@
  */
 #include "shrpx.h"
 
-#include <stdint.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #ifdef HAVE_SYS_SOCKET_H
@@ -59,6 +58,7 @@
 #include <sys/resource.h>
 #include <grp.h>
 
+#include <cinttypes>
 #include <limits>
 #include <cstdlib>
 #include <iostream>
diff --git a/src/shrpx_config.h b/src/shrpx_config.h
index 872bf836..8afccd51 100644
--- a/src/shrpx_config.h
+++ b/src/shrpx_config.h
@@ -27,7 +27,6 @@
 
 #include "shrpx.h"
 
-#include <stdint.h>
 #include <sys/types.h>
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
@@ -39,6 +38,7 @@
 #ifdef HAVE_ARPA_INET_H
 #include <arpa/inet.h>
 #endif // HAVE_ARPA_INET_H
+#include <cinttypes>
 #include <cstdio>
 #include <vector>
 #include <memory>
diff --git a/src/shrpx_downstream.h b/src/shrpx_downstream.h
index f761b6a0..2bd29312 100644
--- a/src/shrpx_downstream.h
+++ b/src/shrpx_downstream.h
@@ -27,8 +27,7 @@
 
 #include "shrpx.h"
 
-#include <stdint.h>
-
+#include <cinttypes>
 #include <vector>
 #include <string>
 #include <memory>
diff --git a/src/shrpx_downstream_queue.h b/src/shrpx_downstream_queue.h
index ee5028bd..d327a05f 100644
--- a/src/shrpx_downstream_queue.h
+++ b/src/shrpx_downstream_queue.h
@@ -27,8 +27,7 @@
 
 #include "shrpx.h"
 
-#include <stdint.h>
-
+#include <cinttypes>
 #include <map>
 #include <set>
 #include <memory>
diff --git a/src/shrpx_https_upstream.h b/src/shrpx_https_upstream.h
index 1b0c648a..3b9d5320 100644
--- a/src/shrpx_https_upstream.h
+++ b/src/shrpx_https_upstream.h
@@ -27,8 +27,7 @@
 
 #include "shrpx.h"
 
-#include <stdint.h>
-
+#include <cinttypes>
 #include <memory>
 
 #include "http-parser/http_parser.h"
diff --git a/src/timegm.c b/src/timegm.c
index bf572b72..90bf53ff 100644
--- a/src/timegm.c
+++ b/src/timegm.c
@@ -26,7 +26,7 @@
 
 #ifndef HAVE_TIMEGM
 
-#include <stdint.h>
+#include <inttypes.h>
 
 /* Counter the number of leap year in the range [0, y). The |y| is the
    year, including century (e.g., 2012) */