diff --git a/emulators/ares.yml b/emulators/ares.yml
index afe61555..4aefd9b3 100644
--- a/emulators/ares.yml
+++ b/emulators/ares.yml
@@ -170,7 +170,7 @@ files:
   # Also used by Mega CD 32X (desktop-ui/emulator/mega-cd-32x.cpp)
   - name: SegaCDBIOS9303.bin
     system: mega-cd
-    region: [north-america]
+    region: [north-america, latin-america]
     required: true
     sha256: "fb477cdbf94c84424c2feca4fe40656d85393fe7b7b401911b45ad2eb991258c"
     validation: [sha256]
diff --git a/emulators/jgenesis.yml b/emulators/jgenesis.yml
index 06f8f1b1..cbd04fe8 100644
--- a/emulators/jgenesis.yml
+++ b/emulators/jgenesis.yml
@@ -77,7 +77,7 @@ files:
   - name: "bios_CD_U.bin"
     system: sega-megacd
     description: "Sega CD BIOS (US)"
-    region: [north-america]
+    region: [north-america, latin-america]
     required: true
     size: 131072
     validation: [size]
diff --git a/emulators/md-emu.yml b/emulators/md-emu.yml
index 8522a9a4..f6d98a90 100644
--- a/emulators/md-emu.yml
+++ b/emulators/md-emu.yml
@@ -94,7 +94,7 @@ notes: |
 files:
   - name: bios_CD_U.bin
     system: sega-megacd
-    region: [north-america]
+    region: [north-america, latin-america]
     required: true
     agnostic: true
     size: 131072
diff --git a/tests/test_region.py b/tests/test_region.py
index 943fe854..372591a5 100644
--- a/tests/test_region.py
+++ b/tests/test_region.py
@@ -1072,5 +1072,27 @@ class ANameNoCodeOpensCarriesNoRegion(unittest.TestCase):
         self.assertNotIn("region", entry)
 
 
+class MegaCdAmericasIsOneCode(unittest.TestCase):
+    """A Sega CD disc carries one region code for all the Americas, so every
+    emulator picking the US BIOS by that code picks it for a Brazilian disc
+    too. jgenesis, md-emu and ares tagged it north-america alone, and a
+    --region brazil pack dropped the BIOS those discs boot with."""
+
+    def test_a_us_mega_cd_bios_includes_latin_america(self):
+        import yaml
+
+        root = Path(__file__).resolve().parents[1]
+        narrow = []
+        for path in sorted((root / "emulators").glob("*.yml")):
+            profile = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
+            for entry in profile.get("files") or []:
+                system = str(entry.get("system", ""))
+                regions = entry.get("region") or []
+                if system in ("sega-megacd", "mega-cd") and "north-america" in regions \
+                        and "latin-america" not in regions:
+                    narrow.append(f"{path.stem}: {entry.get('name')}")
+        self.assertEqual(narrow, [])
+
+
 if __name__ == "__main__":
     unittest.main()