diff --git a/js/src/jit/CodeGenerator.cpp b/js/src/jit/CodeGenerator.cpp
index b6827c5349..e7ac4469e3 100644
--- a/js/src/jit/CodeGenerator.cpp
+++ b/js/src/jit/CodeGenerator.cpp
@@ -3988,6 +3988,13 @@ CodeGenerator::visitPostWriteElementBarrierO(LPostWriteElementBarrierO* lir)
     visitPostWriteBarrierCommon<LPostWriteElementBarrierO, MIRType::Object>(lir, ool);
 }
 
+void
+CodeGenerator::visitPostWriteElementBarrierS(LPostWriteElementBarrierS* lir)
+{
+    auto ool = new(alloc()) OutOfLineCallPostWriteElementBarrier(lir, lir->object(), lir->index());
+    visitPostWriteBarrierCommon<LPostWriteElementBarrierS, MIRType::String>(lir, ool);
+ }
+
 void
 CodeGenerator::visitPostWriteElementBarrierV(LPostWriteElementBarrierV* lir)
 {