diff --git a/io/io_dontwantread.c b/io/io_dontwantread.c
index e0f1e45..34be35f 100644
--- a/io/io_dontwantread.c
+++ b/io/io_dontwantread.c
@@ -8,6 +8,7 @@
 #include <sys/time.h>
 #endif
 #ifdef HAVE_EPOLL
+#include <inttypes.h>
 #include <sys/epoll.h>
 #endif
 
diff --git a/io/io_dontwantwrite.c b/io/io_dontwantwrite.c
index 0584847..769c22b 100644
--- a/io/io_dontwantwrite.c
+++ b/io/io_dontwantwrite.c
@@ -8,6 +8,7 @@
 #include <sys/time.h>
 #endif
 #ifdef HAVE_EPOLL
+#include <inttypes.h>
 #include <sys/epoll.h>
 #endif
 
diff --git a/io/io_fd.c b/io/io_fd.c
index f8f4511..ab3005a 100644
--- a/io/io_fd.c
+++ b/io/io_fd.c
@@ -1,10 +1,11 @@
+#define _GNU_SOURCE
 #define extern
 #include "io_internal.h"
 #undef extern
 #ifdef HAVE_SIGIO
-#define _GNU_SOURCE
 #include <sys/poll.h>
 #include <signal.h>
+#include <fcntl.h>
 #endif
 #include <sys/types.h>
 #include <fcntl.h>
@@ -13,8 +14,10 @@
 #include <sys/event.h>
 #endif
 #ifdef HAVE_EPOLL
+#include <inttypes.h>
 #include <sys/epoll.h>
 #endif
+#include <unistd.h>
 
 /* put d on internal data structure, return 1 on success, 0 on error */
 int io_fd(int64 d) {
diff --git a/io/io_waituntil2.c b/io/io_waituntil2.c
index 3bc5776..cab3469 100644
--- a/io/io_waituntil2.c
+++ b/io/io_waituntil2.c
@@ -11,6 +11,7 @@
 #include <sys/event.h>
 #endif
 #ifdef HAVE_EPOLL
+#include <inttypes.h>
 #include <sys/epoll.h>
 #endif
 
diff --git a/io/io_wantread.c b/io/io_wantread.c
index 2386fed..567cc06 100644
--- a/io/io_wantread.c
+++ b/io/io_wantread.c
@@ -8,6 +8,7 @@
 #include <sys/time.h>
 #endif
 #ifdef HAVE_EPOLL
+#include <inttypes.h>
 #include <sys/epoll.h>
 #endif
 #ifdef HAVE_SIGIO
diff --git a/io/io_wantwrite.c b/io/io_wantwrite.c
index cec001f..12e6b09 100644
--- a/io/io_wantwrite.c
+++ b/io/io_wantwrite.c
@@ -8,6 +8,7 @@
 #include <sys/time.h>
 #endif
 #ifdef HAVE_EPOLL
+#include <inttypes.h>
 #include <sys/epoll.h>
 #endif
 #ifdef HAVE_SIGIO