diff --git a/ets2panda/checker/ETSAnalyzer.cpp b/ets2panda/checker/ETSAnalyzer.cpp
index 3ddb14664f61941fca09872e70ce710dddee9191..62707a62b195465aa11ebc19d331d129ac2dc7a7 100644
--- a/ets2panda/checker/ETSAnalyzer.cpp
+++ b/ets2panda/checker/ETSAnalyzer.cpp
@@ -2992,7 +2992,7 @@ checker::Type *ETSAnalyzer::Check(ir::UpdateExpression *expr) const
         return expr->SetTsType(checker->GlobalTypeError());
     }
 
-    return expr->SetTsType(operandType);
+    return expr->SetTsType(checker->ApplyUnaryOperatorPromotion(expr->argument_, operandType));
 }
 
 // compile methods for LITERAL EXPRESSIONS in alphabetical order