diff --git a/libgo/go/runtime/export_test.go b/libgo/go/runtime/export_test.go
index 6595faf..ab74e34 100644
--- a/libgo/go/runtime/export_test.go
+++ b/libgo/go/runtime/export_test.go
@@ -866,7 +866,7 @@
 //
 // This should not be higher than 0x100*pallocChunkBytes to support
 // mips and mipsle, which only have 31-bit address spaces.
-var BaseChunkIdx = ChunkIdx(chunkIndex(((0xc000*pageAlloc64Bit + 0x100*pageAlloc32Bit) * pallocChunkBytes) + 0x0a00000000000000*sys.GoosAix))
+var BaseChunkIdx = ChunkIdx(chunkIndex(((0xc000*pageAlloc64Bit + 0x100*pageAlloc32Bit) * pallocChunkBytes) + 0x0a00000000000000*sys.GoosAix*sys.GoarchPpc64))
 
 // PageBase returns an address given a chunk index and a page index
 // relative to that chunk.
diff --git a/libgo/go/runtime/malloc.go b/libgo/go/runtime/malloc.go
index 266f5eb..6df7eaa 100644
--- a/libgo/go/runtime/malloc.go
+++ b/libgo/go/runtime/malloc.go
@@ -312,7 +312,7 @@
 	//
 	// On other platforms, the user address space is contiguous
 	// and starts at 0, so no offset is necessary.
-	arenaBaseOffset = sys.GoarchAmd64*(1<<47) + (^0x0a00000000000000+1)&uintptrMask*sys.GoosAix
+	arenaBaseOffset = sys.GoarchAmd64*(1<<47) + (^0x0a00000000000000+1)&uintptrMask*sys.GoosAix*sys.GoarchPpc64
 
 	// Max number of threads to run garbage collection.
 	// 2, 3, and 4 are all plausible maximums depending