diff --git a/js/src/jit/BaselineCompiler.cpp b/js/src/jit/BaselineCompiler.cpp
index 3856fb63f6..38202915a4 100644
--- a/js/src/jit/BaselineCompiler.cpp
+++ b/js/src/jit/BaselineCompiler.cpp
@@ -3937,6 +3937,28 @@ BaselineCompiler::emit_JSOP_TOASYNCGEN()
     return true;
 }
 
+typedef JSObject* (*ToAsyncIterFn)(JSContext*, HandleObject);
+static const VMFunction ToAsyncIterInfo =
+    FunctionInfo<ToAsyncIterFn>(js::CreateAsyncFromSyncIterator, "ToAsyncIter");
+
+bool
+BaselineCompiler::emit_JSOP_TOASYNCITER()
+{
+    frame.syncStack(0);
+    masm.unboxObject(frame.addressOfStackValue(frame.peek(-1)), R0.scratchReg());
+
+    prepareVMCall();
+    pushArg(R0.scratchReg());
+
+    if (!callVM(ToAsyncIterInfo))
+        return false;
+
+    masm.tagValue(JSVAL_TYPE_OBJECT, ReturnReg, R0);
+    frame.pop();
+    frame.push(R0);
+    return true;
+}
+
 typedef bool (*ThrowObjectCoercibleFn)(JSContext*, HandleValue);
 static const VMFunction ThrowObjectCoercibleInfo =
     FunctionInfo<ThrowObjectCoercibleFn>(ThrowObjectCoercible, "ThrowObjectCoercible");
diff --git a/js/src/jit/BaselineCompiler.h b/js/src/jit/BaselineCompiler.h
index 15d0e30645..7b1af092ae 100644
--- a/js/src/jit/BaselineCompiler.h
+++ b/js/src/jit/BaselineCompiler.h
@@ -198,6 +198,7 @@ namespace jit {
     _(JSOP_REST)               \
     _(JSOP_TOASYNC)            \
     _(JSOP_TOASYNCGEN)         \
+    _(JSOP_TOASYNCITER)        \
     _(JSOP_TOID)               \
     _(JSOP_TOSTRING)           \
     _(JSOP_TABLESWITCH)        \
diff --git a/js/src/jit/CodeGenerator.cpp b/js/src/jit/CodeGenerator.cpp
index 128947e5ed..2b1c671d1b 100644
--- a/js/src/jit/CodeGenerator.cpp
+++ b/js/src/jit/CodeGenerator.cpp
@@ -10225,6 +10225,17 @@ CodeGenerator::visitToAsyncGen(LToAsyncGen* lir)
     callVM(ToAsyncGenInfo, lir);
 }
 
+typedef JSObject* (*ToAsyncIterFn)(JSContext*, HandleObject);
+static const VMFunction ToAsyncIterInfo =
+    FunctionInfo<ToAsyncIterFn>(js::CreateAsyncFromSyncIterator, "ToAsyncIter");
+
+void
+CodeGenerator::visitToAsyncIter(LToAsyncIter* lir)
+{
+    pushArg(ToRegister(lir->unwrapped()));
+    callVM(ToAsyncIterInfo, lir);
+}
+
 typedef bool (*ToIdFn)(JSContext*, HandleScript, jsbytecode*, HandleValue,
                        MutableHandleValue);
 static const VMFunction ToIdInfo = FunctionInfo<ToIdFn>(ToIdOperation, "ToIdOperation");
diff --git a/js/src/jit/CodeGenerator.h b/js/src/jit/CodeGenerator.h
index d2f24dc043..65acfe2740 100644
--- a/js/src/jit/CodeGenerator.h
+++ b/js/src/jit/CodeGenerator.h
@@ -287,6 +287,7 @@ class CodeGenerator final : public CodeGeneratorSpecific
     void visitOutOfLineTypeOfV(OutOfLineTypeOfV* ool);
     void visitToAsync(LToAsync* lir);
     void visitToAsyncGen(LToAsyncGen* lir);
+    void visitToAsyncIter(LToAsyncIter* lir);
     void visitToIdV(LToIdV* lir);
     template<typename T> void emitLoadElementT(LLoadElementT* lir, const T& source);
     void visitLoadElementT(LLoadElementT* lir);
diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index 79214c993d..ac56312894 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -2133,6 +2133,9 @@ IonBuilder::inspectOpcode(JSOp op)
       case JSOP_TOASYNCGEN:
         return jsop_toasyncgen();
 
+      case JSOP_TOASYNCITER:
+        return jsop_toasynciter();
+
       case JSOP_TOID:
         return jsop_toid();
 
@@ -13210,6 +13213,20 @@ IonBuilder::jsop_toasyncgen()
     return resumeAfter(ins);
 }
 
+bool
+IonBuilder::jsop_toasynciter()
+{
+    MDefinition* unwrapped = current->pop();
+    MOZ_ASSERT(unwrapped->type() == MIRType::Object);
+
+    MToAsyncIter* ins = MToAsyncIter::New(alloc(), unwrapped);
+
+    current->add(ins);
+    current->push(ins);
+
+    return resumeAfter(ins);
+}
+
 bool
 IonBuilder::jsop_toid()
 {
diff --git a/js/src/jit/IonBuilder.h b/js/src/jit/IonBuilder.h
index 48388539fd..6a3b61232f 100644
--- a/js/src/jit/IonBuilder.h
+++ b/js/src/jit/IonBuilder.h
@@ -763,6 +763,7 @@ class IonBuilder
     MOZ_MUST_USE bool jsop_typeof();
     MOZ_MUST_USE bool jsop_toasync();
     MOZ_MUST_USE bool jsop_toasyncgen();
+    MOZ_MUST_USE bool jsop_toasynciter();
     MOZ_MUST_USE bool jsop_toid();
     MOZ_MUST_USE bool jsop_iter(uint8_t flags);
     MOZ_MUST_USE bool jsop_itermore();
diff --git a/js/src/jit/Lowering.cpp b/js/src/jit/Lowering.cpp
index ee59b8ae60..1084509833 100644
--- a/js/src/jit/Lowering.cpp
+++ b/js/src/jit/Lowering.cpp
@@ -1183,6 +1183,14 @@ LIRGenerator::visitToAsyncGen(MToAsyncGen* ins)
     assignSafepoint(lir, ins);
 }
 
+void
+LIRGenerator::visitToAsyncIter(MToAsyncIter* ins)
+{
+    LToAsyncIter* lir = new(alloc()) LToAsyncIter(useRegisterAtStart(ins->input()));
+    defineReturn(lir, ins);
+    assignSafepoint(lir, ins);
+}
+
 void
 LIRGenerator::visitToId(MToId* ins)
 {
diff --git a/js/src/jit/Lowering.h b/js/src/jit/Lowering.h
index 1d412040c5..81e6abbbbd 100644
--- a/js/src/jit/Lowering.h
+++ b/js/src/jit/Lowering.h
@@ -122,6 +122,7 @@ class LIRGenerator : public LIRGeneratorSpecific
     void visitTypeOf(MTypeOf* ins);
     void visitToAsync(MToAsync* ins);
     void visitToAsyncGen(MToAsyncGen* ins);
+    void visitToAsyncIter(MToAsyncIter* ins);
     void visitToId(MToId* ins);
     void visitBitNot(MBitNot* ins);
     void visitBitAnd(MBitAnd* ins);
diff --git a/js/src/jit/MIR.h b/js/src/jit/MIR.h
index 637c09cfdd..e7186ed305 100644
--- a/js/src/jit/MIR.h
+++ b/js/src/jit/MIR.h
@@ -5799,6 +5799,21 @@ class MToAsyncGen
     TRIVIAL_NEW_WRAPPERS
 };
 
+class MToAsyncIter
+  : public MUnaryInstruction,
+    public SingleObjectPolicy::Data
+{
+    explicit MToAsyncIter(MDefinition* unwrapped)
+      : MUnaryInstruction(unwrapped)
+    {
+        setResultType(MIRType::Object);
+    }
+
+  public:
+    INSTRUCTION_HEADER(ToAsyncIter)
+    TRIVIAL_NEW_WRAPPERS
+};
+
 class MToId
   : public MUnaryInstruction,
     public BoxInputsPolicy::Data
diff --git a/js/src/jit/MOpcodes.h b/js/src/jit/MOpcodes.h
index 59620e4e76..589dde0774 100644
--- a/js/src/jit/MOpcodes.h
+++ b/js/src/jit/MOpcodes.h
@@ -80,6 +80,7 @@ namespace jit {
     _(TypeOf)                                                               \
     _(ToAsync)                                                              \
     _(ToAsyncGen)                                                           \
+    _(ToAsyncIter)                                                          \
     _(ToId)                                                                 \
     _(BitAnd)                                                               \
     _(BitOr)                                                                \
diff --git a/js/src/jit/shared/LIR-shared.h b/js/src/jit/shared/LIR-shared.h
index 6c8ff899b5..ff4915d1a7 100644
--- a/js/src/jit/shared/LIR-shared.h
+++ b/js/src/jit/shared/LIR-shared.h
@@ -1619,6 +1619,19 @@ class LToAsyncGen : public LCallInstructionHelper<1, 1, 0>
     }
 };
 
+class LToAsyncIter : public LCallInstructionHelper<1, 1, 0>
+{
+  public:
+    LIR_HEADER(ToAsyncIter)
+    explicit LToAsyncIter(const LAllocation& input) {
+        setOperand(0, input);
+    }
+
+    const LAllocation* unwrapped() {
+        return getOperand(0);
+    }
+};
+
 class LToIdV : public LInstructionHelper<BOX_PIECES, BOX_PIECES, 1>
 {
   public:
diff --git a/js/src/jit/shared/LOpcodes-shared.h b/js/src/jit/shared/LOpcodes-shared.h
index 9e79f02660..56b98940af 100644
--- a/js/src/jit/shared/LOpcodes-shared.h
+++ b/js/src/jit/shared/LOpcodes-shared.h
@@ -354,6 +354,7 @@
     _(TypeOfV)                      \
     _(ToAsync)                      \
     _(ToAsyncGen)                   \
+    _(ToAsyncIter)                  \
     _(ToIdV)                        \
     _(Floor)                        \
     _(FloorF)                       \