diff --git a/src/system/kernel/vm/VMAnonymousCache.cpp b/src/system/kernel/vm/VMAnonymousCache.cpp
index eff47ce2f6..34b6fa0ebd 100644
--- a/src/system/kernel/vm/VMAnonymousCache.cpp
+++ b/src/system/kernel/vm/VMAnonymousCache.cpp
@@ -1045,10 +1045,13 @@ VMAnonymousCache::Merge(VMCache* _source)
 	_MergeSwapPages(source);
 
 	// Move all not shadowed pages from the source to the consumer cache.
-	if (source->page_count < page_count)
-		_MergePagesSmallerSource(source);
-	else
+	if (source->page_count > page_count
+			&& source->virtual_base == virtual_base
+			&& source->virtual_end == virtual_end) {
 		_MergePagesSmallerConsumer(source);
+	} else {
+		VMCache::Merge(source);
+	}
 }
 
 
@@ -1215,28 +1218,6 @@ VMAnonymousCache::_Commit(off_t size, int priority)
 }
 
 
-void
-VMAnonymousCache::_MergePagesSmallerSource(VMAnonymousCache* source)
-{
-	// The source cache has less pages than the consumer (this cache), so we
-	// iterate through the source's pages and move the ones that are not
-	// shadowed up to the consumer.
-
-	for (VMCachePagesTree::Iterator it = source->pages.GetIterator();
-			vm_page* page = it.Next();) {
-		// Note: Removing the current node while iterating through a
-		// IteratableSplayTree is safe.
-		vm_page* consumerPage = LookupPage(
-			(off_t)page->cache_offset << PAGE_SHIFT);
-		if (consumerPage == NULL) {
-			// the page is not yet in the consumer cache - move it upwards
-			ASSERT_PRINT(!page->busy, "page: %p", page);
-			MovePage(page);
-		}
-	}
-}
-
-
 void
 VMAnonymousCache::_MergePagesSmallerConsumer(VMAnonymousCache* source)
 {
@@ -1244,8 +1225,12 @@ VMAnonymousCache::_MergePagesSmallerConsumer(VMAnonymousCache* source)
 	// consumer's pages to the source (freeing shadowed ones) and finally just
 	// all pages of the source back to the consumer.
 
-	for (VMCachePagesTree::Iterator it = pages.GetIterator();
-		vm_page* page = it.Next();) {
+	// It is possible that some of the pages we are moving here are actually "busy".
+	// Since all the pages that belong to this cache will belong to it again by
+	// the time we unlock, that should be fine.
+
+	VMCachePagesTree::Iterator it = pages.GetIterator();
+	while (vm_page* page = it.Next()) {
 		// If a source page is in the way, remove and free it.
 		vm_page* sourcePage = source->LookupPage(
 			(off_t)page->cache_offset << PAGE_SHIFT);
diff --git a/src/system/kernel/vm/VMAnonymousCache.h b/src/system/kernel/vm/VMAnonymousCache.h
index 1d1142869d..e7150a9fac 100644
--- a/src/system/kernel/vm/VMAnonymousCache.h
+++ b/src/system/kernel/vm/VMAnonymousCache.h
@@ -90,8 +90,6 @@ private:
 			swap_addr_t			_SwapBlockGetAddress(off_t pageIndex);
 			status_t			_Commit(off_t size, int priority);
 
-			void				_MergePagesSmallerSource(
-									VMAnonymousCache* source);
 			void				_MergePagesSmallerConsumer(
 									VMAnonymousCache* source);
 			void				_MergeSwapPages(VMAnonymousCache* source);
diff --git a/src/system/kernel/vm/VMCache.cpp b/src/system/kernel/vm/VMCache.cpp
index 18642aa518..18b83b8e83 100644
--- a/src/system/kernel/vm/VMCache.cpp
+++ b/src/system/kernel/vm/VMCache.cpp
@@ -852,6 +852,7 @@ VMCache::MovePage(vm_page* page, off_t offset)
 
 	AssertLocked();
 	oldCache->AssertLocked();
+	ASSERT(offset >= virtual_base && (offset + B_PAGE_SIZE) <= virtual_end);
 
 	// remove from old cache
 	oldCache->pages.Remove(page);
@@ -1391,8 +1392,14 @@ VMCache::Fault(struct VMAddressSpace *aspace, off_t offset)
 void
 VMCache::Merge(VMCache* source)
 {
-	for (VMCachePagesTree::Iterator it = source->pages.GetIterator();
-			vm_page* page = it.Next();) {
+	const page_num_t firstOffset = ROUNDDOWN(virtual_base, B_PAGE_SIZE) >> PAGE_SHIFT,
+		endOffset = (page_num_t)((virtual_end + B_PAGE_SIZE - 1) >> PAGE_SHIFT);
+
+	VMCachePagesTree::Iterator it = source->pages.GetIterator();
+	while (vm_page* page = it.Next()) {
+		if (page->cache_offset < firstOffset || page->cache_offset >= endOffset)
+			continue;
+
 		// Note: Removing the current node while iterating through a
 		// IteratableSplayTree is safe.
 		vm_page* consumerPage = LookupPage(