diff --git a/src/impl/os.cpp b/src/impl/os.cpp
index 7981470..9591fbc 100644
--- a/src/impl/os.cpp
+++ b/src/impl/os.cpp
@@ -2,6 +2,11 @@
 // Copyright 2014 Perttu Ahola <celeron55@gmail.com>
 #include "interface/os.h"
 #include <sys/time.h>
+#ifdef _WIN32
+	#include "ports/windows_compat.h"
+#else
+	#include <unistd.h>
+#endif
 
 namespace interface {
 namespace os {
@@ -13,6 +18,11 @@ int64_t get_timeofday_us()
 	return (int64_t)tv.tv_sec * 1000000 + (int64_t)tv.tv_usec;
 }
 
+void sleep_us(int us)
+{
+	usleep(us);
+}
+
 }
 }
 // vim: set noet ts=4 sw=4:
diff --git a/src/interface/os.h b/src/interface/os.h
index 46a1080..c1e8af6 100644
--- a/src/interface/os.h
+++ b/src/interface/os.h
@@ -8,6 +8,7 @@ namespace interface
 	namespace os
 	{
 		int64_t get_timeofday_us();
+		void sleep_us(int us);
 	}
 }