diff --git a/hw/sun4m.c b/hw/sun4m.c
index ae9222af1e..89f4b418d2 100644
--- a/hw/sun4m.c
+++ b/hw/sun4m.c
@@ -401,7 +401,7 @@ static const struct hwdef hwdefs[] = {
         .iommu_base   = 0x10000000,
         .tcx_base     = 0x50000000,
         .cs_base      = 0x6c000000,
-        .slavio_base  = 0x71000000,
+        .slavio_base  = 0x70000000,
         .ms_kb_base   = 0x71000000,
         .serial_base  = 0x71100000,
         .nvram_base   = 0x71200000,
@@ -433,7 +433,7 @@ static const struct hwdef hwdefs[] = {
         .iommu_base   = 0xe0000000, // XXX Actually at 0xfe0000000ULL (36 bits)
         .tcx_base     = 0x20000000, // 0xe20000000ULL,
         .cs_base      = -1,
-        .slavio_base  = 0xf1000000, // 0xff1000000ULL,
+        .slavio_base  = 0xf0000000, // 0xff0000000ULL,
         .ms_kb_base   = 0xf1000000, // 0xff1000000ULL,
         .serial_base  = 0xf1100000, // 0xff1100000ULL,
         .nvram_base   = 0xf1200000, // 0xff1200000ULL,