diff --git a/repos/base-hw/src/lib/hw/spec/x86_64/page_table.h b/repos/base-hw/src/lib/hw/spec/x86_64/page_table.h
index 02692b7a4f..163accce43 100644
--- a/repos/base-hw/src/lib/hw/spec/x86_64/page_table.h
+++ b/repos/base-hw/src/lib/hw/spec/x86_64/page_table.h
@@ -515,6 +515,7 @@ class Hw::Pml4_table
 
 		static constexpr size_t PAGE_SIZE_LOG2 = SIZE_LOG2_512GB;
 		static constexpr size_t SIZE_LOG2      = SIZE_LOG2_256TB;
+		static constexpr size_t SIZE_MASK      = (1UL << SIZE_LOG2) - 1;
 		static constexpr size_t MAX_ENTRIES    = 512;
 		static constexpr size_t PAGE_SIZE      = 1UL << PAGE_SIZE_LOG2;
 		static constexpr size_t PAGE_MASK      = ~((1UL << PAGE_SIZE_LOG2) - 1);
@@ -593,8 +594,8 @@ class Hw::Pml4_table
 		template <typename FUNC>
 		void _range_op(addr_t vo, addr_t pa, size_t size, FUNC &&func)
 		{
-			for (size_t i = vo >> PAGE_SIZE_LOG2; size > 0;
-			     i = vo >> PAGE_SIZE_LOG2) {
+			for (size_t i = (vo & SIZE_MASK) >> PAGE_SIZE_LOG2; size > 0;
+			     i = (vo & SIZE_MASK) >> PAGE_SIZE_LOG2) {
 				assert (i < MAX_ENTRIES);
 				addr_t end = (vo + PAGE_SIZE) & PAGE_MASK;
 				size_t sz  = Genode::min(size, end-vo);