diff --git a/include/cutils/qtaguid.h b/include/cutils/qtaguid.h
index dd2db52..8aa34ea 100644
--- a/include/cutils/qtaguid.h
+++ b/include/cutils/qtaguid.h
@@ -19,6 +19,7 @@
 
 #include <stdint.h>
 #include <sys/types.h>
+#include <unistd.h>
 
 #ifdef __cplusplus
 extern "C" {