diff --git a/commonItems/Linguistics/adjective_rules.txt b/commonItems/Linguistics/adjective_rules.txt
index d7e84b86..2691ac33 100644
--- a/commonItems/Linguistics/adjective_rules.txt
+++ b/commonItems/Linguistics/adjective_rules.txt
@@ -556,6 +556,7 @@
 {"*ah", "*ah"},
 {"*aí", "*aian"}, // Kolōnaí (Colonae in Latin) -> Kolonaian (rule made up)
 {"*ai", "*aian"}, // Kolōnai
+{"*aj", "*ajian"}, // Thaj (place in Arabia), rule made up
 {"*al", "*ali"}, // Nepal
 {"*an", "*anian"}, // Jordan
 {"*ao", "*aoan"}, // Curaçao
@@ -601,6 +602,7 @@
 {"*ík", "*ikian"}, // Reykjavík
 {"*jh", "*jhi"}, // Wajh
 {"*ju", "*ju"}, // Gwangju
+{"*jo", "*joan"}, // Blaikingawjo, rule made up
 {"*fi", "*fitan"}, // Amalfi
 {"*ff", "*ffian"}, // Cardiff
 {"*le", "*lean"}, // Chile
diff --git a/commonItems/Parser.cs b/commonItems/Parser.cs
index aaaa50a2..9f5e2f11 100644
--- a/commonItems/Parser.cs
+++ b/commonItems/Parser.cs
@@ -254,7 +254,11 @@ public static string GetNextLexeme(BufferedReader reader) {
 		}
 		var lexeme = GetNextLexeme(reader);
 		if (CommonRegexes.Variable.IsMatch(lexeme)) {
-			return GetValueString(reader.ResolveVariable(lexeme));
+			var variableValue = reader.ResolveVariable(lexeme);
+			if (variableValue is null) {
+				return null;
+			}
+			return GetValueString(variableValue);
 		}
 		if (CommonRegexes.InterpolatedExpression.IsMatch(lexeme)) {
 			return GetValueString(reader.EvaluateExpression(lexeme));
diff --git a/commonItems/commonItems.csproj b/commonItems/commonItems.csproj
index d7b4c8fa..41777a59 100644
--- a/commonItems/commonItems.csproj
+++ b/commonItems/commonItems.csproj
@@ -6,7 +6,7 @@
 
     <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
     <PackageId>PGCG.$(AssemblyName)</PackageId>
-    <Version>10.0.3</Version>
+    <Version>10.0.4</Version>
     <Authors>PGCG</Authors>
     <PackageProjectUrl>https://github.com/ParadoxGameConverters/commonItems.NET</PackageProjectUrl>
     <RepositoryUrl>https://github.com/ParadoxGameConverters/commonItems.NET</RepositoryUrl>