diff --git a/Content.Tests/DMProject/Tests/Arg/ProcArgumentGlobal_lint.dm b/Content.Tests/DMProject/Tests/Arg/ProcArgumentGlobal_lint.dm
new file mode 100644
index 0000000000..5356fb9aad
--- /dev/null
+++ b/Content.Tests/DMProject/Tests/Arg/ProcArgumentGlobal_lint.dm
@@ -0,0 +1,8 @@
+// COMPILE ERROR OD2211
+#pragma ProcArgumentGlobal error
+
+/proc/foo(/var/bar)
+	return
+
+/proc/RunTest()
+	return
diff --git a/DMCompiler/Compiler/CompilerError.cs b/DMCompiler/Compiler/CompilerError.cs
index ed7f43bd81..92781d038e 100644
--- a/DMCompiler/Compiler/CompilerError.cs
+++ b/DMCompiler/Compiler/CompilerError.cs
@@ -49,6 +49,7 @@ public enum WarningCode {
     FallbackBuiltinArgument = 2208, // A builtin (sin(), cos(), etc) with an invalid/fallback argument
     PointlessScopeOperator = 2209,
     PointlessPositionalArgument = 2210,
+    ProcArgumentGlobal = 2211, // Prepending "/" on a proc arg (e.g. "/proc/example(/var/foo)" makes the arg a global var. Ref https://www.byond.com/forum/post/2830750
     MalformedRange = 2300,
     InvalidRange = 2301,
     InvalidSetStatement = 2302,
diff --git a/DMCompiler/Compiler/DM/DMParser.cs b/DMCompiler/Compiler/DM/DMParser.cs
index 48612218b8..bf7e025353 100644
--- a/DMCompiler/Compiler/DM/DMParser.cs
+++ b/DMCompiler/Compiler/DM/DMParser.cs
@@ -1723,6 +1723,10 @@ private List<DMASTDefinitionParameter> DefinitionParameters(out bool wasIndeterm
             DMASTPath? path = Path();
 
             if (path != null) {
+                if (path.Path.PathString.StartsWith("/var/")) {
+                    Emit(WarningCode.ProcArgumentGlobal, $"Proc argument \"{path.Path.PathString}\" starting with \"/var/\" will create a global variable. Replace with \"{path.Path.PathString[1..]}\"");
+                }
+
                 var loc = Current().Location;
                 Whitespace();
 
diff --git a/DMCompiler/DMStandard/DefaultPragmaConfig.dm b/DMCompiler/DMStandard/DefaultPragmaConfig.dm
index c91ebb324d..c67eb91610 100644
--- a/DMCompiler/DMStandard/DefaultPragmaConfig.dm
+++ b/DMCompiler/DMStandard/DefaultPragmaConfig.dm
@@ -31,6 +31,7 @@
 #pragma AmbiguousResourcePath warning
 #pragma SuspiciousSwitchCase warning
 #pragma PointlessPositionalArgument warning
+#pragma ProcArgumentGlobal warning // Ref BYOND issue https://www.byond.com/forum/post/2830750
 // NOTE: The next few pragmas are for OpenDream's experimental type checker
 // This feature is still in development, elevating these pragmas outside of local testing is discouraged
 // An RFC to finalize this feature is coming soon(TM)