diff --git a/documentation/RELEASE_NOTES.html b/documentation/RELEASE_NOTES.html
index 8361621c8..b2e5fdc65 100644
--- a/documentation/RELEASE_NOTES.html
+++ b/documentation/RELEASE_NOTES.html
@@ -20,6 +20,11 @@
 
 -->
 
+<h3>Callback subsystem API</h3>
+
+<p>Added a new macro <tt>callbackGetPriority(prio, callback)</tt> to the
+callback.h header and removed the need for dbScan.c to reach into the internals
+of its CALLBACK objects.</p>
 
 </body>
 </html>
diff --git a/src/ioc/db/callback.h b/src/ioc/db/callback.h
index 2732f9d5e..66a949036 100644
--- a/src/ioc/db/callback.h
+++ b/src/ioc/db/callback.h
@@ -47,14 +47,16 @@ typedef struct callbackPvt {
 
 typedef void    (*CALLBACKFUNC)(struct callbackPvt*);
 
-#define callbackSetCallback(PFUN,PCALLBACK)\
-( (PCALLBACK)->callback = (PFUN) )
-#define callbackSetPriority(PRIORITY,PCALLBACK)\
-( (PCALLBACK)->priority = (PRIORITY) )
-#define callbackSetUser(USER,PCALLBACK)\
-( (PCALLBACK)->user = (void *)(USER) )
-#define callbackGetUser(USER,PCALLBACK)\
-( (USER) = (void *)((CALLBACK *)(PCALLBACK))->user )
+#define callbackSetCallback(PFUN, PCALLBACK) \
+    ( (PCALLBACK)->callback = (PFUN) )
+#define callbackSetPriority(PRIORITY, PCALLBACK) \
+    ( (PCALLBACK)->priority = (PRIORITY) )
+#define callbackGetPriority(PRIORITY, PCALLBACK) \
+    ( (PRIORITY) = (PCALLBACK)->priority )
+#define callbackSetUser(USER, PCALLBACK) \
+    ( (PCALLBACK)->user = (void *) (USER) )
+#define callbackGetUser(USER, PCALLBACK) \
+    ( (USER) = (PCALLBACK)->user )
 
 epicsShareFunc void callbackInit(void);
 epicsShareFunc void callbackShutdown(void);
diff --git a/src/ioc/db/dbScan.c b/src/ioc/db/dbScan.c
index ba927a04b..08c5c4af3 100644
--- a/src/ioc/db/dbScan.c
+++ b/src/ioc/db/dbScan.c
@@ -813,9 +813,11 @@ static void spawnPeriodic(int ind)
 
 static void ioscanCallback(CALLBACK *pcallback)
 {
-    ioscan_head *piosh = (ioscan_head *) pcallback->user;
-    int prio = pcallback->priority;
+    ioscan_head *piosh;
+    int prio;
 
+    callbackGetUser(piosh, pcallback);
+    callbackGetPriority(prio, pcallback);
     scanList(&piosh->iosl[prio].scan_list);
     if (piosh->cb)
         piosh->cb(piosh->arg, piosh, prio);