diff --git a/src/libCom/misc/epicsTypes.h b/src/libCom/misc/epicsTypes.h
index ef9f790fc..711f75364 100644
--- a/src/libCom/misc/epicsTypes.h
+++ b/src/libCom/misc/epicsTypes.h
@@ -26,6 +26,11 @@
 #   endif
 #endif
 
+typedef enum {
+    epicsFalse = 0,
+    epicsTrue  = 1
+} epicsBoolean;
+
 /*
  * Architecture Independent Data Types
  * These are sufficient for all our current archs