diff --git a/src/libCom/osi/os/posix/osdSignal.c b/src/libCom/osi/os/posix/osdSignal.c
index d255fa27c..b1cfa03f6 100644
--- a/src/libCom/osi/os/posix/osdSignal.c
+++ b/src/libCom/osi/os/posix/osdSignal.c
@@ -14,6 +14,7 @@
 #include <string.h>
 
 #define epicsExportSharedSymbols
+#include "epicsThread.h"
 #include "epicsSignal.h"
 
 typedef void ( *pSigFunc ) ( int );