diff --git a/src/Makefile b/src/Makefile
index 6d6b9d7..44d77de 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -3,6 +3,18 @@
 TOP = ..
 include $(TOP)/configure/CONFIG
 
+EPICS_PVA_MAJOR_VERSION = 4
+EPICS_PVA_MINOR_VERSION = 2
+EPICS_PVA_MAINTENANCE_VERSION = 0
+EPICS_PVA_DEVELOPMENT_FLAG = 1
+
+EXPANDVARS += EPICS_PVA_MAJOR_VERSION
+EXPANDVARS += EPICS_PVA_MINOR_VERSION
+EXPANDVARS += EPICS_PVA_MAINTENANCE_VERSION
+EXPANDVARS += EPICS_PVA_DEVELOPMENT_FLAG
+
+EXPANDFLAGS += $(foreach var,$(EXPANDVARS),-D$(var)="$(strip $($(var)))")
+
 INSTALL_INCLUDE = $(INSTALL_LOCATION)/include/pv
 USR_INCLUDES += -I$(INSTALL_LOCATION)/include
 
@@ -33,3 +45,7 @@ pvAccess_SYS_LIBS_WIN32 += ws2_32
 
 include $(TOP)/configure/RULES
 
+# Can't use EXPAND as generated headers must appear
+# in O.Common, but EXPAND emits rules for O.$(T_A)
+../O.Common/pvaVersionNum.h: pvaVersionNum.h@
+	$(EXPAND_TOOL) $(EXPANDFLAGS) $($@_EXPANDFLAGS) $< $@
diff --git a/src/pva/Makefile b/src/pva/Makefile
index ae58254..e68702d 100644
--- a/src/pva/Makefile
+++ b/src/pva/Makefile
@@ -4,6 +4,7 @@ SRC_DIRS += $(PVACCESS_SRC)/pva
 
 INC += pvaConstants.h
 INC += pvaVersion.h
+INC += pvaVersionNum.h
 INC += clientFactory.h
 
 LIBSRCS += pvaVersion.cpp
diff --git a/src/pva/pvaVersion.h b/src/pva/pvaVersion.h
index 8714ef0..969c5b2 100644
--- a/src/pva/pvaVersion.h
+++ b/src/pva/pvaVersion.h
@@ -22,12 +22,7 @@
 
 #include <shareLib.h>
 
-// module version
-// TODO to be generated, etc.
-#define EPICS_PVA_MAJOR_VERSION 4
-#define EPICS_PVA_MINOR_VERSION 2 
-#define EPICS_PVA_MAINTENANCE_VERSION 0
-#define EPICS_PVA_DEVELOPMENT_FLAG 1
+#include "pvaVersionNum.h"
 
 namespace epics {
 namespace pvAccess {
diff --git a/src/pva/pvaVersionNum.h@ b/src/pva/pvaVersionNum.h@
new file mode 100644
index 0000000..65d9a9e
--- /dev/null
+++ b/src/pva/pvaVersionNum.h@
@@ -0,0 +1,7 @@
+#ifndef VERSION_H_
+#  error include pvaVersion.h, not this header
+#endif
+#define EPICS_PVA_MAJOR_VERSION @EPICS_PVA_MAJOR_VERSION@
+#define EPICS_PVA_MINOR_VERSION @EPICS_PVA_MINOR_VERSION@
+#define EPICS_PVA_MAINTENANCE_VERSION @EPICS_PVA_MAINTENANCE_VERSION@
+#define EPICS_PVA_DEVELOPMENT_FLAG @EPICS_PVA_DEVELOPMENT_FLAG@