diff --git a/main.go b/main.go
index eb67a08a5..0f7b21bd1 100644
--- a/main.go
+++ b/main.go
@@ -92,7 +92,7 @@ func parse(binary []byte) (metadata maxminddb.Metadata, countryMap map[string][]
 			return
 		}
 		// idk why
-		code := country.RegisteredCountry.IsoCode
+		code := strings.ToLower(country.RegisteredCountry.IsoCode)
 		countryMap[code] = append(countryMap[code], ipNet)
 	}
 	err = networks.Err()