diff --git a/src/misc/timer.cpp b/src/misc/timer.cpp
index bdaafc1..eb5ca00 100644
--- a/src/misc/timer.cpp
+++ b/src/misc/timer.cpp
@@ -16,6 +16,8 @@
 #include <string>
 #include <iostream>
 
+#include <epicsThread.h>
+
 #define epicsExportSharedSymbols
 #include <pv/timer.h>