diff --git a/src/boehm_gc.c b/src/boehm_gc.c
index ed7aca9f05..f88095ddeb 100644
--- a/src/boehm_gc.c
+++ b/src/boehm_gc.c
@@ -76,14 +76,14 @@ void MakeBagTypePublic(int type)
 Bag MakeBagPublic(Bag bag)
 {
     MEMBAR_WRITE();
-    REGION(bag) = 0;
+    SET_REGION(bag, 0);
     return bag;
 }
 
 Bag MakeBagReadOnly(Bag bag)
 {
     MEMBAR_WRITE();
-    REGION(bag) = ReadOnlyRegion;
+    SET_REGION(bag, ReadOnlyRegion);
     return bag;
 }
 
@@ -424,7 +424,7 @@ void RetypeBag(Bag bag, UInt new_type)
 #ifdef HPCGAP
     switch (DSInfoBags[new_type]) {
     case DSI_PUBLIC:
-        REGION(bag) = NULL;
+        SET_REGION(bag, NULL);
         break;
     }
 #endif // HPCGAP
@@ -500,10 +500,10 @@ Bag NewBag(UInt type, UInt size)
 #ifdef HPCGAP
     switch (DSInfoBags[type]) {
     case DSI_TL:
-        REGION(bag) = CurrentRegion();
+        SET_REGION(bag, CurrentRegion());
         break;
     case DSI_PUBLIC:
-        REGION(bag) = NULL;
+        SET_REGION(bag, NULL);
         break;
     }
 #endif
diff --git a/src/debug.c b/src/debug.c
index e91f74398f..6a4b21de7e 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -5,6 +5,10 @@
 #include "calls.h"
 #include "fibhash.h"
 
+#ifdef HPCGAP
+#include "hpc/region.h"
+#endif
+
 #if defined(HAVE_BACKTRACE) && defined(PRINT_BACKTRACE)
 #include <execinfo.h>
 #include <signal.h>
@@ -391,6 +395,8 @@ VoidFunc debug_func_pointers[] = {
     (VoidFunc)ATOMIC_SET_ELM_PLIST,
     (VoidFunc)GetTLS,
     (VoidFunc)LCKS_FUNC,
+    (VoidFunc)REGION,
     (VoidFunc)SET_LCKS_FUNC,
+    (VoidFunc)SET_REGION,
 #endif
 };
diff --git a/src/hpc/aobjects.c b/src/hpc/aobjects.c
index ca292831aa..f0ce7fa3d1 100644
--- a/src/hpc/aobjects.c
+++ b/src/hpc/aobjects.c
@@ -1181,7 +1181,7 @@ static Obj NewTLRecord(Obj defaults, Obj constructors) {
   ADDR_OBJ(inner)[TLR_SIZE] = 0;
   ADDR_OBJ(inner)[TLR_DEFAULTS] = CreateTLDefaults(defaults);
   WriteGuard(constructors);
-  REGION(constructors) = LimboRegion;
+  SET_REGION(constructors, LimboRegion);
   MEMBAR_WRITE();
   ADDR_OBJ(inner)[TLR_CONSTRUCTORS] = NewAtomicRecordFrom(constructors);
   ((AtomicObj *)(ADDR_OBJ(result)))->obj = inner;
diff --git a/src/hpc/region.h b/src/hpc/region.h
index b0959212da..4d9156c039 100644
--- a/src/hpc/region.h
+++ b/src/hpc/region.h
@@ -39,7 +39,15 @@ Region *NewRegion(void);
 **
 **  RegionBag() also contains a memory barrier.
 */
-#define REGION(bag) (((Region **)(bag))[1])
+static inline Region * REGION(Obj bag)
+{
+    return ((Region **)bag)[1];
+}
+
+static inline void SET_REGION(Obj bag, Region * region)
+{
+    ((Region **)bag)[1] = region;
+}
 
 Region *RegionBag(Bag bag);
 
diff --git a/src/hpc/threadapi.c b/src/hpc/threadapi.c
index 6ce3e67c01..c7052d4a8f 100644
--- a/src/hpc/threadapi.c
+++ b/src/hpc/threadapi.c
@@ -358,7 +358,7 @@ pthread_mutex_t KeepAliveLock;
 Obj KeepAlive(Obj obj)
 {
     Obj newKeepAlive = NewBag(T_PLIST, 4 * sizeof(Obj));
-    REGION(newKeepAlive) = NULL;    // public region
+    SET_REGION(newKeepAlive, NULL);    // public region
     pthread_mutex_lock(&KeepAliveLock);
     ADDR_OBJ(newKeepAlive)[0] = (Obj)3; /* Length 3 */
     KEPTALIVE(newKeepAlive) = obj;
@@ -413,7 +413,7 @@ Obj FuncCreateThread(Obj self, Obj funcargs)
             "CreateThread: Needs at least one function argument");
     templist = NEW_PLIST(T_PLIST, n);
     SET_LEN_PLIST(templist, n);
-    REGION(templist) = NULL; /* make it public */
+    SET_REGION(templist, NULL); /* make it public */
     for (i = 1; i <= n; i++)
         SET_ELM_PLIST(templist, i, ELM_PLIST(funcargs, i));
     thread = RunThread(ThreadedInterpreter, KeepAlive(templist));
@@ -1012,7 +1012,7 @@ static void ExpandChannel(Channel * channel)
     Obj  newqueue;
     newqueue = NEW_PLIST(T_PLIST, newCapacity);
     SET_LEN_PLIST(newqueue, newCapacity);
-    REGION(newqueue) = REGION(channel->queue);
+    SET_REGION(newqueue, REGION(channel->queue));
     channel->capacity = newCapacity;
     for (i = channel->head; i < oldCapacity; i++)
         ADDR_OBJ(newqueue)[i + 1] = ADDR_OBJ(channel->queue)[i + 1];
@@ -1045,7 +1045,7 @@ static void AddToChannel(Channel * channel, Obj obj, int migrate)
     }
     for (i = 1; i <= len; i++) {
         Obj item = ELM_PLIST(children, i);
-        REGION(item) = region;
+        SET_REGION(item, region);
     }
     ADDR_OBJ(channel->queue)[++channel->tail] = obj;
     ADDR_OBJ(channel->queue)[++channel->tail] = children;
@@ -1066,7 +1066,7 @@ static Obj RetrieveFromChannel(Channel * channel)
         channel->head = 0;
     for (i = 1; i <= len; i++) {
         Obj item = ELM_PLIST(children, i);
-        REGION(item) = region;
+        SET_REGION(item, region);
     }
     channel->size -= 2;
     return obj;
@@ -1286,7 +1286,7 @@ static Obj CreateChannel(int capacity)
     channel->dynamic = (capacity < 0);
     channel->waiting = 0;
     channel->queue = NEW_PLIST(T_PLIST, channel->capacity);
-    REGION(channel->queue) = LimboRegion;
+    SET_REGION(channel->queue, LimboRegion);
     SET_LEN_PLIST(channel->queue, channel->capacity);
     return channelBag;
 }
@@ -2030,13 +2030,13 @@ MigrateObjects(int count, Obj * objects, Region * target, int retype)
     for (i = 0; i < count; i++) {
         Region * region;
         if (IS_BAG_REF(objects[i])) {
-            region = (Region *)(REGION(objects[i]));
+            region = REGION(objects[i]);
             if (!region || region->owner != GetTLS())
                 return 0;
         }
     }
     for (i = 0; i < count; i++)
-        REGION(objects[i]) = target;
+        SET_REGION(objects[i], target);
     return 1;
 }
 
diff --git a/src/objects.c b/src/objects.c
index 0010ff179e..ccb701f944 100644
--- a/src/objects.c
+++ b/src/objects.c
@@ -1905,7 +1905,7 @@ Obj FuncCLONE_OBJ (
     memcpy(pdst, psrc, SIZE_OBJ(src));
     CHANGED_BAG(dst);
 #ifdef HPCGAP
-    REGION(dst) = REGION(src);
+    SET_REGION(dst, REGION(src));
     MEMBAR_WRITE();
     /* The following is a no-op unless the region is public */
     SET_PTR_BAG(dst, PTR_BAG(tmp));
@@ -1942,8 +1942,8 @@ Obj FuncSWITCH_OBJ(Obj self, Obj obj1, Obj obj2) {
         ErrorQuit("SWITCH_OBJ: Cannot write to first object's region.", 0, 0);
     if (!ds2 || ds2->owner != GetTLS())
         ErrorQuit("SWITCH_OBJ: Cannot write to second object's region.", 0, 0);
-    REGION(obj2) = ds1;
-    REGION(obj1) = ds2;
+    SET_REGION(obj2, ds1);
+    SET_REGION(obj1, ds2);
 #endif
     SwapMasterPoint(obj1, obj2);
     CHANGED_BAG(obj1);
@@ -1987,9 +1987,9 @@ Obj FuncFORCE_SWITCH_OBJ(Obj self, Obj obj1, Obj obj2) {
         ErrorQuit("FORCE_SWITCH_OBJ: Cannot write to first object's region.", 0, 0);
     if (ds2 && ds2->owner != GetTLS())
         ErrorQuit("FORCE_SWITCH_OBJ: Cannot write to second object's region.", 0, 0);
-    REGION(obj2) = ds1;
+    SET_REGION(obj2, ds1);
     SET_PTR_BAG(obj2, ptr1);
-    REGION(obj1) = ds2;
+    SET_REGION(obj1, ds2);
     SET_PTR_BAG(obj1, ptr2);
     CHANGED_BAG(obj1);
     CHANGED_BAG(obj2);
diff --git a/src/opers.c b/src/opers.c
index f19fdedd7a..f7b2c63e3c 100644
--- a/src/opers.c
+++ b/src/opers.c
@@ -4219,8 +4219,8 @@ static Int InitLibrary (
     AssGVar(GVarName("HIDDEN_IMPS"), HIDDEN_IMPS);
 
 #ifdef HPCGAP
-    REGION(HIDDEN_IMPS) = NewRegion();
-    REGION(WITH_HIDDEN_IMPS_FLAGS_CACHE) = REGION(HIDDEN_IMPS);
+    SET_REGION(HIDDEN_IMPS, NewRegion());
+    SET_REGION(WITH_HIDDEN_IMPS_FLAGS_CACHE, REGION(HIDDEN_IMPS));
 #endif
 
     IMPLICATIONS_SIMPLE = NEW_PLIST(T_PLIST, 0);
@@ -4231,9 +4231,9 @@ static Int InitLibrary (
     AssGVar(GVarName("IMPLICATIONS_COMPOSED"), IMPLICATIONS_COMPOSED);
 
 #ifdef HPCGAP
-    REGION(IMPLICATIONS_SIMPLE) = NewRegion();
-    REGION(IMPLICATIONS_COMPOSED) = REGION(IMPLICATIONS_SIMPLE);
-    REGION(WITH_IMPS_FLAGS_CACHE) = REGION(IMPLICATIONS_SIMPLE);
+    SET_REGION(IMPLICATIONS_SIMPLE, NewRegion());
+    SET_REGION(IMPLICATIONS_COMPOSED, REGION(IMPLICATIONS_SIMPLE));
+    SET_REGION(WITH_IMPS_FLAGS_CACHE, REGION(IMPLICATIONS_SIMPLE));
 #endif
 
     /* make the 'true' operation                                           */