diff --git a/Content.Tests/DMProject/Tests/Preprocessor/number_in_arg.dm b/Content.Tests/DMProject/Tests/Preprocessor/number_in_arg.dm
new file mode 100644
index 0000000000..a353f04cfc
--- /dev/null
+++ b/Content.Tests/DMProject/Tests/Preprocessor/number_in_arg.dm
@@ -0,0 +1,4 @@
+#define MACRO(ARG_1, ARG_2) "[#ARG_1] [##ARG_2]"
+
+/proc/RunTest()
+	ASSERT(MACRO(1, 2) == "1 2")
\ No newline at end of file
diff --git a/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs b/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs
index 659cc3c03b..3d02133665 100644
--- a/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs
+++ b/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs
@@ -442,7 +442,7 @@ public Token NextToken(bool ignoreWhitespace = false) {
                 }
 
                 TokenTextBuilder.Clear();
-                while (char.IsAsciiLetter(GetCurrent()) || GetCurrent() == '_') {
+                while (char.IsAsciiLetterOrDigit(GetCurrent()) || GetCurrent() == '_') {
                     TokenTextBuilder.Append(GetCurrent());
                     Advance();
                 }