diff --git a/configure/os/CONFIG.Common.vxWorksCommon b/configure/os/CONFIG.Common.vxWorksCommon
index e1adbe8f6..2203d276d 100644
--- a/configure/os/CONFIG.Common.vxWorksCommon
+++ b/configure/os/CONFIG.Common.vxWorksCommon
@@ -159,7 +159,7 @@ export TOOL_FAMILY = GNU
 
 #--------------------------------------------------
 # Operating system flags
-OP_SYS_CPPFLAGS += -DvxWorks
+OP_SYS_CPPFLAGS += -DvxWorks=vxWorks
 OP_SYS_CFLAGS += -fno-builtin
 
 # Fix for vxWorks 5 headers that use macros defined in vxWorks.h but