diff --git a/include/mruby/dump.h b/include/mruby/dump.h
index 8b78e74d0..b344e2a65 100644
--- a/include/mruby/dump.h
+++ b/include/mruby/dump.h
@@ -15,7 +15,6 @@ extern "C" {
 #ifdef ENABLE_STDIO
 #include <stdio.h>
 #endif
-#include <stdint.h>
 
 #ifdef ENABLE_STDIO
 int mrb_dump_irep(mrb_state*,int,FILE*);
diff --git a/include/mruby/khash.h b/include/mruby/khash.h
index 839221e84..bbb419d0b 100644
--- a/include/mruby/khash.h
+++ b/include/mruby/khash.h
@@ -12,7 +12,6 @@ extern "C" {
 #endif
 
 #include "mruby.h"
-#include <stdint.h>
 #include <string.h>
 
 typedef uint32_t khint_t;
diff --git a/src/string.c b/src/string.c
index d474f6f96..26acfdcb4 100644
--- a/src/string.c
+++ b/src/string.c
@@ -6,7 +6,6 @@
 
 #include "mruby.h"
 
-#include <stdint.h>
 #include <stddef.h>
 #include <string.h>
 #include "mruby/string.h"