diff --git a/mps/code/arenavm.c b/mps/code/arenavm.c
index 4bb65dddccf..928696b4298 100644
--- a/mps/code/arenavm.c
+++ b/mps/code/arenavm.c
@@ -682,7 +682,7 @@ static void tablePagesUsed(Index *tableBaseReturn, Index *tableLimitReturn,
   *tableLimitReturn =
     PageTablePageIndex(chunk,
                        AddrAlignUp(addrOfPageDesc(chunk, pageLimit),
-		                   ChunkPageSize(chunk)));
+                                   ChunkPageSize(chunk)));
   return;
 }
 
@@ -714,8 +714,8 @@ static Res tablePagesEnsureMapped(VMChunk vmChunk,
  
   while(BTFindLongResRange(&unmappedBaseIndex, &unmappedLimitIndex,
                            vmChunk->pageTableMapped,
-		           tableCursorIndex, tableLimitIndex,
-		           1)) {
+                           tableCursorIndex, tableLimitIndex,
+                           1)) {
     Addr unmappedBase = TablePageIndexBase(chunk, unmappedBaseIndex);
     Addr unmappedLimit = TablePageIndexBase(chunk, unmappedLimitIndex);
     /* There might be a page descriptor overlapping the beginning */
@@ -1213,7 +1213,7 @@ static Res pagesMarkAllocated(VMArena vmArena, VMChunk vmChunk,
     while(pageIsMapped(vmChunk, mappedLimit)) {
       ++mappedLimit;
       if (mappedLimit >= limitIndex)
-	break;
+        break;
     }
     AVER(mappedLimit <= limitIndex);
     /* NB for loop will loop 0 times iff first page is not mapped */
@@ -1232,8 +1232,8 @@ static Res pagesMarkAllocated(VMArena vmArena, VMChunk vmChunk,
     }
     AVER(unmappedLimit <= limitIndex);
     res = vmArenaMap(vmArena, vmChunk->vm,
-		     PageIndexBase(chunk, unmappedBase),
-		     PageIndexBase(chunk, unmappedLimit));
+                     PageIndexBase(chunk, unmappedBase),
+                     PageIndexBase(chunk, unmappedLimit));
     if (res != ResOK)
       goto failPagesMap;
     for(i = unmappedBase; i < unmappedLimit; ++i) {
@@ -1250,8 +1250,8 @@ failPagesMap:
   /* region from baseIndex to mappedLimit needs unmapping */
   if (baseIndex < mappedLimit) {
     vmArenaUnmap(vmArena, vmChunk->vm,
-		 PageIndexBase(chunk, baseIndex),
-		 PageIndexBase(chunk, mappedLimit));
+                 PageIndexBase(chunk, baseIndex),
+                 PageIndexBase(chunk, mappedLimit));
     /* mark pages as free */
     for(i = baseIndex; i < mappedLimit; ++i) {
       TractFinish(PageTract(&chunk->pageTable[i]));
@@ -1337,7 +1337,7 @@ static Res vmAllocComm(Addr *baseReturn, Tract *baseTractReturn,
       sparePagesPurge(vmArena);
       res = pagesMarkAllocated(vmArena, vmChunk, baseIndex, pages, pool);
       if (res != ResOK)
-	goto failPagesMap;
+        goto failPagesMap;
       /* win! */
     } else {
       goto failPagesMap;
@@ -1404,13 +1404,13 @@ static void spareRangesMap(VMChunk vmChunk, Index base, Index limit,
     while(!pageIsSpare(&chunk->pageTable[spareBase])) {
       ++spareBase;
       if (spareBase >= limit)
-	goto done;
+        goto done;
     }
     spareLimit = spareBase;
     while(pageIsSpare(&chunk->pageTable[spareLimit])) {
       ++spareLimit;
       if (spareLimit >= limit)
-	break;
+        break;
     }
     f(vmChunk, spareBase, spareLimit, p);
     spareBase = spareLimit;
@@ -1439,7 +1439,7 @@ static void vmArenaUnmapSpareRange(VMChunk vmChunk,
   }
   vmArenaUnmap(VMChunkVMArena(vmChunk), vmChunk->vm,
                PageIndexBase(chunk, rangeBase),
-	       PageIndexBase(chunk, rangeLimit));
+               PageIndexBase(chunk, rangeLimit));
 
   return;
 }
@@ -1465,8 +1465,8 @@ static void sparePagesPurge(VMArena vmArena)
 
     while(BTFindLongResRange(&spareBaseIndex, &spareLimitIndex,
                              vmChunk->noSparePages,
-	           	     tablePageCursor, chunk->pageTablePages,
-	      	             1)) {
+                             tablePageCursor, chunk->pageTablePages,
+                             1)) {
       Addr spareTableBase, spareTableLimit;
       Index pageBase, pageLimit;
       Index tablePage;
@@ -1476,43 +1476,43 @@ static void sparePagesPurge(VMArena vmArena)
       /* Determine whether to use initial overlapping PageStruct. */
       if (spareBaseIndex > 0
           && !BTGet(vmChunk->pageTableMapped, spareBaseIndex - 1)) {
-	pageBase = tablePageWholeBaseIndex(chunk, spareTableBase);
+        pageBase = tablePageWholeBaseIndex(chunk, spareTableBase);
       } else {
         pageBase = tablePageBaseIndex(chunk, spareTableBase);
       }
       for(tablePage = spareBaseIndex; tablePage < spareLimitIndex;
           ++tablePage) {
-	/* Determine whether to use final overlapping PageStruct. */
+        /* Determine whether to use final overlapping PageStruct. */
         if (tablePage == spareLimitIndex - 1
             && spareLimitIndex < chunk->pageTablePages
             && !BTGet(vmChunk->pageTableMapped, spareLimitIndex)) {
-	  pageLimit =
-	    tablePageWholeLimitIndex(chunk,
-	                             TablePageIndexBase(chunk, tablePage));
-	} else if (tablePage == chunk->pageTablePages - 1) {
-	  pageLimit = chunk->pages;
-	} else {
-	  pageLimit =
-	    tablePageLimitIndex(chunk, TablePageIndexBase(chunk, tablePage));
-	}
-	if (pageBase < pageLimit) {
-	  spareRangesMap(vmChunk, pageBase, pageLimit,
+          pageLimit =
+            tablePageWholeLimitIndex(chunk,
+                                     TablePageIndexBase(chunk, tablePage));
+        } else if (tablePage == chunk->pageTablePages - 1) {
+          pageLimit = chunk->pages;
+        } else {
+          pageLimit =
+            tablePageLimitIndex(chunk, TablePageIndexBase(chunk, tablePage));
+        }
+        if (pageBase < pageLimit) {
+          spareRangesMap(vmChunk, pageBase, pageLimit,
                          vmArenaUnmapSpareRange, NULL);
-	} else {
-	  /* Only happens for last page occupied by the page table */
-	  /* and only then when that last page has just the tail end */
-	  /* part of the last page descriptor and nothing more. */
-	  AVER(pageBase == pageLimit);
-	  AVER(tablePage == chunk->pageTablePages - 1);
-	}
-	BTSet(vmChunk->noSparePages, tablePage);
-	pageBase = pageLimit;
+        } else {
+          /* Only happens for last page occupied by the page table */
+          /* and only then when that last page has just the tail end */
+          /* part of the last page descriptor and nothing more. */
+          AVER(pageBase == pageLimit);
+          AVER(tablePage == chunk->pageTablePages - 1);
+        }
+        BTSet(vmChunk->noSparePages, tablePage);
+        pageBase = pageLimit;
       }
       tablePagesUnmapUnused(vmChunk, spareTableBase, spareTableLimit);
       tablePageCursor = spareLimitIndex;
       if (tablePageCursor >= chunk->pageTablePages) {
         AVER(tablePageCursor == chunk->pageTablePages);
-	break;
+        break;
       }
     }