diff --git a/motorApp/MotorSimSrc/Makefile b/motorApp/MotorSimSrc/Makefile
index eee9cf02..cfde6f15 100644
--- a/motorApp/MotorSimSrc/Makefile
+++ b/motorApp/MotorSimSrc/Makefile
@@ -22,6 +22,7 @@ motorSimSupport_SRCS += motorSimDriver.cpp
 motorSimSupport_SRCS += motorSimRegister.cc
 
 motorSimSupport_LIBS += motor
+motorSimSupport_LIBS += asyn
 motorSimSupport_LIBS += $(EPICS_BASE_IOC_LIBS)
 
 #=============================