diff --git a/OpenRA.Game/Support/VariableExpression.cs b/OpenRA.Game/Support/VariableExpression.cs
index bd3844dc08..56ee524e2e 100644
--- a/OpenRA.Game/Support/VariableExpression.cs
+++ b/OpenRA.Game/Support/VariableExpression.cs
@@ -334,6 +334,15 @@ namespace OpenRA.Support
 				return false;
 			}
 
+			static TokenType VariableOrKeyword(string expression, int start, ref int i)
+			{
+				if (CharClassOf(expression[i - 1]) == CharClass.Mixed)
+					throw new InvalidDataException("Invalid identifier end character at index {0} for `{1}`".F(
+						i - 1, expression.Substring(start, i - start)));
+
+				return VariableOrKeyword(expression, start, i - start);
+			}
+
 			static TokenType VariableOrKeyword(string expression, int start, int length)
 			{
 				var i = start;
@@ -464,10 +473,10 @@ namespace OpenRA.Support
 				{
 					cc = CharClassOf(expression[i]);
 					if (cc == CharClass.Whitespace || cc == CharClass.Operator)
-						return VariableOrKeyword(expression, start, i - start);
+						return VariableOrKeyword(expression, start, ref i);
 				}
 
-				return VariableOrKeyword(expression, start, i - start);
+				return VariableOrKeyword(expression, start, ref i);
 			}
 
 			public static Token GetNext(string expression, ref int i, TokenType lastType = TokenType.Invalid)
diff --git a/OpenRA.Test/OpenRA.Game/VariableExpressionTest.cs b/OpenRA.Test/OpenRA.Game/VariableExpressionTest.cs
index 9ed8aae81a..0b9da2243a 100644
--- a/OpenRA.Test/OpenRA.Game/VariableExpressionTest.cs
+++ b/OpenRA.Test/OpenRA.Game/VariableExpressionTest.cs
@@ -351,13 +351,24 @@ namespace OpenRA.Test
 		public void TestParseHyphenErrors()
 		{
 			AssertParseFailure("-", "Missing value or sub-expression at end for `-` operator");
-			AssertParseFailure("t- 1", "Missing binary operation before `1` at index 3");
-			AssertParseFailure("t -1", "Missing binary operation before `-1` at index 2");
 			AssertParseFailure("-1-1", "Missing binary operation before `-1` at index 2");
 			AssertParseFailure("5-1", "Missing binary operation before `-1` at index 1");
 			AssertParseFailure("6 -3", "Missing binary operation before `-3` at index 2");
 		}
 
+		[TestCase(TestName = "Test mixed charaters at end of identifier parser errors")]
+		public void TestParseMixedEndErrors()
+		{
+			AssertParseFailure("t- 1", "Invalid identifier end character at index 1 for `t-`");
+			AssertParseFailure("t-", "Invalid identifier end character at index 1 for `t-`");
+			AssertParseFailure("t. 1", "Invalid identifier end character at index 1 for `t.`");
+			AssertParseFailure("t.", "Invalid identifier end character at index 1 for `t.`");
+			AssertParseFailure("t@ 1", "Invalid identifier end character at index 1 for `t@`");
+			AssertParseFailure("t@", "Invalid identifier end character at index 1 for `t@`");
+			AssertParseFailure("t$ 1", "Invalid identifier end character at index 1 for `t$`");
+			AssertParseFailure("t$", "Invalid identifier end character at index 1 for `t$`");
+		}
+
 		[TestCase(TestName = "Undefined symbols are treated as `false` (0) values")]
 		public void TestUndefinedSymbols()
 		{