diff --git a/src/frontend/compiler.nim b/src/frontend/compiler.nim
index e42dff8..070ca77 100644
--- a/src/frontend/compiler.nim
+++ b/src/frontend/compiler.nim
@@ -1431,6 +1431,8 @@ proc unpackGenerics(self: Compiler, condition: Expression, list: var seq[tuple[m
     case condition.kind:
         of identExpr:
             list.add((accept, self.inferOrError(condition)))
+            if list[^1].kind.kind == Auto:
+                self.error("automatic types cannot be used within generics", condition)
         of binaryExpr:
             let condition = BinaryExpr(condition)
             case condition.operator.lexeme: