diff --git a/src/config.c b/src/config.c
index 6399c91ab..4b94fb2ac 100644
--- a/src/config.c
+++ b/src/config.c
@@ -718,6 +718,20 @@ load_sound(void)
 
     mpu401_standalone_enable = !!ini_section_get_int(cat, "mpu401_standalone", 0);
 
+    /* Backwards compatibility for standalone SSI-2001, CMS and GUS from v3.11 and older. */
+    char *legacy_cards[][2] = {{"ssi2001", "ssi2001"}, {"gameblaster", "cms"}, {"gus", "gus"}};
+    for (int i = 0, j = 0; i < (sizeof(legacy_cards) / sizeof(legacy_cards[0])); i++) {
+        if (ini_section_get_int(cat, legacy_cards[i][0], 0) == 1) {
+            /* Migrate to the first available sound card slot. */
+            for (; j < (sizeof(sound_card_current) / sizeof(sound_card_current[0])); j++) {
+                if (!sound_card_current[j]) {
+                    sound_card_current[j] = sound_card_get_from_internal_name(legacy_cards[i][1]);
+                    break;
+                }
+            }
+        }
+    }
+
     memset(temp, '\0', sizeof(temp));
     p = ini_section_get_string(cat, "sound_type", "float");
     if (strlen(p) > 511)
@@ -2159,7 +2173,7 @@ save_machine(void)
     else
         ini_section_delete_var(cat, "cpu_override");
 
-    /* Forwards compatibility with the previous CPU model system. */
+    /* Downgrade compatibility with the previous CPU model system. */
     ini_section_delete_var(cat, "cpu_manufacturer");
     ini_section_delete_var(cat, "cpu");
 
@@ -2390,6 +2404,23 @@ save_sound(void)
     else
         ini_section_set_int(cat, "mpu401_standalone", mpu401_standalone_enable);
 
+    /* Downgrade compatibility for standalone SSI-2001, CMS and GUS from v3.11 and older. */
+    char *legacy_cards[][2] = {{"ssi2001", "ssi2001"}, {"gameblaster", "cms"}, {"gus", "gus"}};
+    for (int i = 0; i < (sizeof(legacy_cards) / sizeof(legacy_cards[0])); i++) {
+        int card_id = sound_card_get_from_internal_name(legacy_cards[i][1]);
+        for (int j = 0; j < (sizeof(sound_card_current) / sizeof(sound_card_current[0])); j++) {
+            if (sound_card_current[j] == card_id) {
+                /* A special value of 2 still enables the cards on older versions,
+                   but lets newer versions know that they've already been migrated. */
+                ini_section_set_int(cat, legacy_cards[i][0], 2);
+                card_id = 0; /* mark as found */
+                break;
+            }
+        }
+        if (card_id > 0) /* not found */
+            ini_section_delete_var(cat, legacy_cards[i][0]);
+    }
+
     if (sound_is_float == 1)
         ini_section_delete_var(cat, "sound_type");
     else