diff --git a/roms/seabios-hppa b/roms/seabios-hppa
index 4c6ecda618..e4eac85880 160000
--- a/roms/seabios-hppa
+++ b/roms/seabios-hppa
@@ -1 +1 @@
-Subproject commit 4c6ecda618f2066707f50c53f31419244fd7f77a
+Subproject commit e4eac85880e8677f96d8b9e94de9f2eec9c0751f
diff --git a/target/hppa/mem_helper.c b/target/hppa/mem_helper.c
index 08abd1a9f9..4c28c58ee9 100644
--- a/target/hppa/mem_helper.c
+++ b/target/hppa/mem_helper.c
@@ -55,8 +55,14 @@ hwaddr hppa_abs_to_phys_pa2_w0(vaddr addr)
         /* I/O address space */
         addr = (int32_t)addr;
     } else {
-        /* PDC address space */
-        addr &= MAKE_64BIT_MASK(0, 24);
+        /*
+         * PDC address space:
+         * Figures H-10 and H-11 of the parisc2.0 spec do not specify
+         * where to map into the 64-bit PDC address space.
+         * We map with an offset which equals the 32-bit address, which
+         * is what can be seen on physical machines too.
+         */
+        addr = (uint32_t)addr;
         addr |= -1ull << (TARGET_PHYS_ADDR_SPACE_BITS - 4);
     }
     return addr;