diff --git a/src/threading/thread.h b/src/threading/thread.h
index 3c8447b53..cd46856e9 100644
--- a/src/threading/thread.h
+++ b/src/threading/thread.h
@@ -32,7 +32,10 @@ DEALINGS IN THE SOFTWARE.
 
 #include <string>
 #if USE_CPP11_THREADS
-	#include <thread>
+	#include <thread> // for std::thread
+#endif
+#ifdef _AIX
+	#include <sys/thread.h> // for tid_t
 #endif
 
 /*