diff --git a/qom/object.c b/qom/object.c
index 44ec8f6460..157a45c5f8 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -157,14 +157,6 @@ static bool type_name_is_valid(const char *name)
                         "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                         "0123456789-_.");
 
-    /* Allow some legacy names with '+' in it for compatibility reasons */
-    if (name[plen] == '+') {
-        if (plen >= 17 && g_str_has_prefix(name, "Sun-UltraSparc-I")) {
-            /* Allow "Sun-UltraSparc-IV+" and "Sun-UltraSparc-IIIi+" */
-            return true;
-        }
-    }
-
     return plen == slen;
 }
 
diff --git a/target/sparc/cpu.c b/target/sparc/cpu.c
index 485d416925..7487ae034d 100644
--- a/target/sparc/cpu.c
+++ b/target/sparc/cpu.c
@@ -314,7 +314,7 @@ static const sparc_def_t sparc_defs[] = {
         .features = CPU_DEFAULT_FEATURES,
     },
     {
-        .name = "Sun UltraSparc IV+",
+        .name = "Sun UltraSparc IV plus",
         .iu_version = ((0x3eULL << 48) | (0x19ULL << 32) | (0x22ULL << 24)),
         .fpu_version = 0x00000000,
         .mmu_version = mmu_us_12,
@@ -323,7 +323,7 @@ static const sparc_def_t sparc_defs[] = {
         .features = CPU_DEFAULT_FEATURES | CPU_FEATURE_CMT,
     },
     {
-        .name = "Sun UltraSparc IIIi+",
+        .name = "Sun UltraSparc IIIi plus",
         .iu_version = ((0x3eULL << 48) | (0x22ULL << 32) | (0ULL << 24)),
         .fpu_version = 0x00000000,
         .mmu_version = mmu_us_3,
@@ -762,6 +762,16 @@ static ObjectClass *sparc_cpu_class_by_name(const char *cpu_model)
     char *typename;
 
     typename = sparc_cpu_type_name(cpu_model);
+
+    /* Fix up legacy names with '+' in it */
+    if (g_str_equal(typename, SPARC_CPU_TYPE_NAME("Sun-UltraSparc-IV+"))) {
+        g_free(typename);
+        typename = g_strdup(SPARC_CPU_TYPE_NAME("Sun-UltraSparc-IV-plus"));
+    } else if (g_str_equal(typename, SPARC_CPU_TYPE_NAME("Sun-UltraSparc-IIIi+"))) {
+        g_free(typename);
+        typename = g_strdup(SPARC_CPU_TYPE_NAME("Sun-UltraSparc-IIIi-plus"));
+    }
+
     oc = object_class_by_name(typename);
     g_free(typename);
     return oc;