diff --git a/stage23/protos/stivale.c b/stage23/protos/stivale.c
index a0440b27..15df9f0e 100644
--- a/stage23/protos/stivale.c
+++ b/stage23/protos/stivale.c
@@ -427,7 +427,7 @@ pagemap_t stivale_build_pagemap(bool level5pg, bool unmap_null, struct elf_range
     //
     //     start = 0x200000
     //     end   = 0x40000000
-    //     
+    //
     //     pages_required = (end - start) / (4096 * 512 * 512)
     //
     // So we map 2MiB to 1GiB with 2MiB pages and then map the rest
@@ -460,14 +460,14 @@ pagemap_t stivale_build_pagemap(bool level5pg, bool unmap_null, struct elf_range
         if (base >= top)
             continue;
 
-        uint64_t aligned_base   = ALIGN_DOWN(base, 0x200000);
-        uint64_t aligned_top    = ALIGN_UP(top, 0x200000);
+        uint64_t aligned_base   = ALIGN_DOWN(base, 0x40000000);
+        uint64_t aligned_top    = ALIGN_UP(top, 0x40000000);
         uint64_t aligned_length = aligned_top - aligned_base;
 
-        for (uint64_t j = 0; j < aligned_length; j += 0x200000) {
+        for (uint64_t j = 0; j < aligned_length; j += 0x40000000) {
             uint64_t page = aligned_base + j;
-            map_page(pagemap, page, page, 0x03, Size2MiB);
-            map_page(pagemap, direct_map_offset + page, page, 0x03, Size2MiB);
+            map_page(pagemap, page, page, 0x03, Size1GiB);
+            map_page(pagemap, direct_map_offset + page, page, 0x03, Size1GiB);
         }
     }
 
diff --git a/stage23/protos/stivale2.c b/stage23/protos/stivale2.c
index 13d8853e..ebd8334e 100644
--- a/stage23/protos/stivale2.c
+++ b/stage23/protos/stivale2.c
@@ -243,7 +243,13 @@ failed_to_load_header_section:
                 panic(true, "stivale2: Requested HHDM slide alignment is not a multiple of 2MiB");
             }
 
-            direct_map_offset += (rand64() & ~(slt->alignment - 1)) & 0xffffffffff;
+            // XXX: Assert that slt->alignment is not larger than 1GiB and ignore the value altogether.
+            //      This is required for 1GiB pages.
+            if (((uint64_t)0x40000000 % slt->alignment) != 0) {
+                panic(true, "stivale2: 1 GiB is not a multiple of HHDM slide alignment");
+            }
+
+            direct_map_offset += (rand64() & ~((uint64_t)0x40000000 - 1)) & 0xfffffffffff;
         }
     }