diff --git a/lib/IRGen/IRGenSIL.cpp b/lib/IRGen/IRGenSIL.cpp
index af85953d60673..d966a39e28b90 100644
--- a/lib/IRGen/IRGenSIL.cpp
+++ b/lib/IRGen/IRGenSIL.cpp
@@ -656,6 +656,10 @@ class IRGenSILFunction :
   bool emitLifetimeExtendingUse(llvm::Value *Var) {
     llvm::Type *ArgTys;
     auto *Ty = Var->getType();
+    // Avoid to emit when Wasm because of lack of register.
+    if (IGM.TargetInfo.OutputObjectFormat == llvm::Triple::Wasm) {
+      return false;
+    }
     // Vectors, Pointers and Floats are expected to fit into a register.
     if (Ty->isPointerTy() || Ty->isFloatingPointTy() || Ty->isVectorTy())
       ArgTys = {Ty};