diff --git a/Sources/SwiftSovereignStates/Country.swift b/Sources/SwiftSovereignStates/Country.swift
index dc5ecde..3895000 100644
--- a/Sources/SwiftSovereignStates/Country.swift
+++ b/Sources/SwiftSovereignStates/Country.swift
@@ -318,11 +318,11 @@ public enum Country : String, CaseIterable, SovereignState {
     }
     
     public func getAdditionalKeywords() -> [String]? {
-        var keywords:[String] = [String]()
+        var keywords:[String] = getSovereignStateAdditionalKeywords() ?? [String]()
         if let parentISOAlpha2:String = getISOAlpha2ParentGroup() {
             keywords.append(parentISOAlpha2)
         }
-        return keywords
+        return keywords.isEmpty ? nil : keywords
     }
     
     public func getWikipediaURL() -> String {
diff --git a/Sources/SwiftSovereignStates/SovereignState.swift b/Sources/SwiftSovereignStates/SovereignState.swift
index b054121..3154e75 100644
--- a/Sources/SwiftSovereignStates/SovereignState.swift
+++ b/Sources/SwiftSovereignStates/SovereignState.swift
@@ -14,7 +14,7 @@ public protocol SovereignState : SovereignRegion {
     func getISOAlpha3() -> String?
 }
 public extension SovereignState {
-    func getAdditionalKeywords() -> [String]? {
+    func getSovereignStateAdditionalKeywords() -> [String]? {
         var keywords:[String] = [String]()
         if let isoAlpha2:String = getISOAlpha2() {
             keywords.append(isoAlpha2)
@@ -22,6 +22,9 @@ public extension SovereignState {
         if let isoAlpha3:String = getISOAlpha3() {
             keywords.append(isoAlpha3)
         }
-        return keywords
+        return keywords.isEmpty ? nil : keywords
+    }
+    func getAdditionalKeywords() -> [String]? {
+        return getSovereignStateAdditionalKeywords()
     }
 }
diff --git a/Tests/SwiftSovereignStatesTests/SwiftSovereignStates.swift b/Tests/SwiftSovereignStatesTests/SwiftSovereignStates.swift
index 4fe9ee6..b965a45 100644
--- a/Tests/SwiftSovereignStatesTests/SwiftSovereignStates.swift
+++ b/Tests/SwiftSovereignStatesTests/SwiftSovereignStates.swift
@@ -247,6 +247,8 @@ final class SwiftSovereignStatesTests: XCTestCase {
             print("SwiftSovereignStatesTests;testCountryMentions;shouldn't be=[" + notMentioned.map({ $0.getIdentifier() }).joined(separator: ",") + "]")
         }
         XCTAssert(mentioned.count == targetCountries.count)
+        
+        XCTAssert(Country.valueOf("USA") != nil)
     }
     private func testSubdivisionMentions() {
         let targetSubdivisions:[any SovereignStateSubdivision] = [SubdivisionsMexico.baja_california, SubdivisionsUnitedStates.california]