diff --git a/mrbgems/mruby-bin-debugger/tools/mrdb/mrdb.c b/mrbgems/mruby-bin-debugger/tools/mrdb/mrdb.c
index d2fa4c856..8fab3c2e8 100644
--- a/mrbgems/mruby-bin-debugger/tools/mrdb/mrdb.c
+++ b/mrbgems/mruby-bin-debugger/tools/mrdb/mrdb.c
@@ -5,7 +5,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
 #include <ctype.h>
 
 #include <mruby.h>
diff --git a/mrbgems/mruby-bin-debugger/tools/mrdb/mrdbconf.h b/mrbgems/mruby-bin-debugger/tools/mrdb/mrdbconf.h
index de2f90144..080b0616b 100644
--- a/mrbgems/mruby-bin-debugger/tools/mrdb/mrdbconf.h
+++ b/mrbgems/mruby-bin-debugger/tools/mrdb/mrdbconf.h
@@ -7,7 +7,11 @@
 #define MRDBCONF_H
 
 #ifndef MRB_ENABLE_DEBUG_HOOK
-# error Need 'MRB_ENABLE_DEBUG_HOOK' configuration in your 'build_config.rb'
+# error mruby-bin-debugger need 'MRB_ENABLE_DEBUG_HOOK' configuration in your 'build_config.rb'
+#endif
+
+#ifdef MRB_DISABLE_STDIO
+# error mruby-bin-debugger conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
 #endif
 
 /* configuration options: */
diff --git a/mrbgems/mruby-bin-mirb/tools/mirb/mirb.c b/mrbgems/mruby-bin-mirb/tools/mirb/mirb.c
index ac6276dc2..fb973207f 100644
--- a/mrbgems/mruby-bin-mirb/tools/mirb/mirb.c
+++ b/mrbgems/mruby-bin-mirb/tools/mirb/mirb.c
@@ -7,6 +7,11 @@
 */
 
 #include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error mruby-bin-mirb conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include <mruby/array.h>
 #include <mruby/proc.h>
 #include <mruby/compile.h>
@@ -17,7 +22,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
 #include <ctype.h>
 
 #include <signal.h>
diff --git a/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c b/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c
index 716b79c88..bdc3925b0 100644
--- a/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c
+++ b/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c
@@ -1,7 +1,11 @@
-#include <stdio.h>
+#include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error mruby-bin-mrbc conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include <stdlib.h>
 #include <string.h>
-#include <mruby.h>
 #include <mruby/compile.h>
 #include <mruby/dump.h>
 #include <mruby/proc.h>
diff --git a/mrbgems/mruby-bin-mruby/tools/mruby/mruby.c b/mrbgems/mruby-bin-mruby/tools/mruby/mruby.c
index f3593aa48..e5c8f3466 100644
--- a/mrbgems/mruby-bin-mruby/tools/mruby/mruby.c
+++ b/mrbgems/mruby-bin-mruby/tools/mruby/mruby.c
@@ -1,7 +1,11 @@
-#include <stdio.h>
+#include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error mruby-bin-mruby conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include <stdlib.h>
 #include <string.h>
-#include <mruby.h>
 #include <mruby/array.h>
 #include <mruby/compile.h>
 #include <mruby/dump.h>
diff --git a/mrbgems/mruby-bin-strip/tools/mruby-strip/mruby-strip.c b/mrbgems/mruby-bin-strip/tools/mruby-strip/mruby-strip.c
index fb78b0c3b..3d05238d2 100644
--- a/mrbgems/mruby-bin-strip/tools/mruby-strip/mruby-strip.c
+++ b/mrbgems/mruby-bin-strip/tools/mruby-strip/mruby-strip.c
@@ -1,7 +1,11 @@
-#include <stdio.h>
+#include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error mruby-bin-strip conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include <stdlib.h>
 #include <string.h>
-#include <mruby.h>
 #include <mruby/irep.h>
 #include <mruby/dump.h>
 
diff --git a/mrbgems/mruby-io/include/mruby/ext/io.h b/mrbgems/mruby-io/include/mruby/ext/io.h
index c4eccb936..38ed0f222 100644
--- a/mrbgems/mruby-io/include/mruby/ext/io.h
+++ b/mrbgems/mruby-io/include/mruby/ext/io.h
@@ -5,6 +5,12 @@
 #ifndef MRUBY_IO_H
 #define MRUBY_IO_H
 
+#include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error IO and File conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #if defined(__cplusplus)
 extern "C" {
 #endif
diff --git a/mrbgems/mruby-io/src/file_test.c b/mrbgems/mruby-io/src/file_test.c
index aadd1ac1c..d75cbd598 100644
--- a/mrbgems/mruby-io/src/file_test.c
+++ b/mrbgems/mruby-io/src/file_test.c
@@ -28,7 +28,6 @@
 #include <fcntl.h>
 
 #include <errno.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/mrbgems/mruby-io/src/io.c b/mrbgems/mruby-io/src/io.c
index 41d6b6120..8b0dcb244 100644
--- a/mrbgems/mruby-io/src/io.c
+++ b/mrbgems/mruby-io/src/io.c
@@ -55,7 +55,6 @@ typedef mrb_int pid_t;
 #include <fcntl.h>
 
 #include <errno.h>
-#include <stdio.h>
 #include <string.h>
 
 #define OPEN_ACCESS_MODE_FLAGS (O_RDONLY | O_WRONLY | O_RDWR)
diff --git a/mrbgems/mruby-io/test/mruby_io_test.c b/mrbgems/mruby-io/test/mruby_io_test.c
index 581472eaa..44b8acebb 100644
--- a/mrbgems/mruby-io/test/mruby_io_test.c
+++ b/mrbgems/mruby-io/test/mruby_io_test.c
@@ -56,7 +56,6 @@ mkdtemp(char *temp)
 #endif
 
 #include <sys/stat.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 #include "mruby.h"
diff --git a/mrbgems/mruby-pack/src/pack.c b/mrbgems/mruby-pack/src/pack.c
index 73b6ce635..a5cd7efed 100644
--- a/mrbgems/mruby-pack/src/pack.c
+++ b/mrbgems/mruby-pack/src/pack.c
@@ -2,7 +2,12 @@
  ** pack.c - Array#pack, String#unpack
  */
 
-#include "mruby.h"
+#include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error pack/unpack conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include "mruby/error.h"
 #include "mruby/array.h"
 #include "mruby/class.h"
@@ -13,7 +18,6 @@
 #include <ctype.h>
 #include <errno.h>
 #include <limits.h>
-#include <stdio.h>
 #include <string.h>
 
 struct tmpl {
diff --git a/mrbgems/mruby-print/src/print.c b/mrbgems/mruby-print/src/print.c
index f7f99fc77..66d070f60 100644
--- a/mrbgems/mruby-print/src/print.c
+++ b/mrbgems/mruby-print/src/print.c
@@ -1,6 +1,10 @@
 #include <mruby.h>
+
+#ifdef MRB_DISABLE_STDIO
+# error print conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include <mruby/string.h>
-#include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #if defined(_WIN32)
diff --git a/mrbgems/mruby-socket/test/sockettest.c b/mrbgems/mruby-socket/test/sockettest.c
index e9247d030..02eb1e1a8 100644
--- a/mrbgems/mruby-socket/test/sockettest.c
+++ b/mrbgems/mruby-socket/test/sockettest.c
@@ -1,4 +1,3 @@
-#include <stdio.h>
 #include <stdlib.h>
 
 #include "mruby.h"
diff --git a/mrbgems/mruby-sprintf/src/sprintf.c b/mrbgems/mruby-sprintf/src/sprintf.c
index 6e4d8fd7e..558d57173 100644
--- a/mrbgems/mruby-sprintf/src/sprintf.c
+++ b/mrbgems/mruby-sprintf/src/sprintf.c
@@ -6,8 +6,11 @@
 
 #include <mruby.h>
 
+#ifdef MRB_DISABLE_STDIO
+# error sprintf conflicts 'MRB_DISABLE_STDIO' configuration in your 'build_config.rb'
+#endif
+
 #include <limits.h>
-#include <stdio.h>
 #include <string.h>
 #include <mruby/string.h>
 #include <mruby/hash.h>
diff --git a/mrbgems/mruby-time/src/time.c b/mrbgems/mruby-time/src/time.c
index 5ce43e465..5cd4abe6d 100644
--- a/mrbgems/mruby-time/src/time.c
+++ b/mrbgems/mruby-time/src/time.c
@@ -14,9 +14,7 @@
 #include <mruby/numeric.h>
 #include <mruby/time.h>
 
-#ifndef MRB_DISABLE_STDIO
-#include <stdio.h>
-#else
+#ifdef MRB_DISABLE_STDIO
 #include <string.h>
 #endif