diff --git a/js/src/jit/CodeGenerator.cpp b/js/src/jit/CodeGenerator.cpp
index 8602da66b638..40b3586c7120 100644
--- a/js/src/jit/CodeGenerator.cpp
+++ b/js/src/jit/CodeGenerator.cpp
@@ -11626,6 +11626,22 @@ CodeGenerator::visitCheckReturn(LCheckReturn* ins)
     masm.bind(&noChecks);
 }
 
+typedef bool (*ThrowCheckIsObjectFn)(JSContext*, CheckIsObjectKind);
+static const VMFunction ThrowCheckIsObjectInfo =
+    FunctionInfo<ThrowCheckIsObjectFn>(ThrowCheckIsObject, "ThrowCheckIsObject");
+
+void
+CodeGenerator::visitCheckIsObj(LCheckIsObj* ins)
+{
+    ValueOperand checkValue = ToValue(ins, LCheckIsObj::CheckValue);
+
+    OutOfLineCode* ool = oolCallVM(ThrowCheckIsObjectInfo, ins,
+                                   ArgList(Imm32(ins->mir()->checkKind())),
+                                   StoreNothing());
+    masm.branchTestObject(Assembler::NotEqual, checkValue, ool->entry());
+    masm.bind(ool->rejoin());
+}
+
 typedef bool (*ThrowObjCoercibleFn)(JSContext*, HandleValue);
 static const VMFunction ThrowObjectCoercibleInfo =
     FunctionInfo<ThrowObjCoercibleFn>(ThrowObjectCoercible, "ThrowObjectCoercible");
diff --git a/js/src/jit/CodeGenerator.h b/js/src/jit/CodeGenerator.h
index 074bdecac131..f61c2d718019 100644
--- a/js/src/jit/CodeGenerator.h
+++ b/js/src/jit/CodeGenerator.h
@@ -373,6 +373,7 @@ class CodeGenerator final : public CodeGeneratorSpecific
     void visitNewTarget(LNewTarget* ins);
     void visitArrowNewTarget(LArrowNewTarget* ins);
     void visitCheckReturn(LCheckReturn* ins);
+    void visitCheckIsObj(LCheckIsObj* ins);
     void visitCheckObjCoercible(LCheckObjCoercible* ins);
     void visitDebugCheckSelfHosted(LDebugCheckSelfHosted* ins);
 
diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index 61508cf16096..33b76673ee6c 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -2145,6 +2145,9 @@ IonBuilder::inspectOpcode(JSOp op)
       case JSOP_NEWTARGET:
         return jsop_newtarget();
 
+      case JSOP_CHECKISOBJ:
+        return jsop_checkisobj(GET_UINT8(pc));
+
       case JSOP_CHECKOBJCOERCIBLE:
         return jsop_checkobjcoercible();
 
@@ -10794,6 +10797,22 @@ IonBuilder::jsop_rest()
     return true;
 }
 
+bool
+IonBuilder::jsop_checkisobj(uint8_t kind)
+{
+    MDefinition* toCheck = current->peek(-1);
+
+    if (toCheck->type() == MIRType::Object) {
+        toCheck->setImplicitlyUsedUnchecked();
+        return true;
+    }
+
+    MCheckIsObj* check = MCheckIsObj::New(alloc(), current->pop(), kind);
+    current->add(check);
+    current->push(check);
+    return true;
+}
+
 bool
 IonBuilder::jsop_checkobjcoercible()
 {
diff --git a/js/src/jit/IonBuilder.h b/js/src/jit/IonBuilder.h
index f0e0ad10ae72..4d6e4a5996c0 100644
--- a/js/src/jit/IonBuilder.h
+++ b/js/src/jit/IonBuilder.h
@@ -780,6 +780,7 @@ class IonBuilder
     MOZ_MUST_USE bool jsop_setaliasedvar(ScopeCoordinate sc);
     MOZ_MUST_USE bool jsop_debugger();
     MOZ_MUST_USE bool jsop_newtarget();
+    MOZ_MUST_USE bool jsop_checkisobj(uint8_t kind);
     MOZ_MUST_USE bool jsop_checkobjcoercible();
 
     /* Inlining. */
diff --git a/js/src/jit/Lowering.cpp b/js/src/jit/Lowering.cpp
index 19b455cbfea1..413cdf11a2f7 100644
--- a/js/src/jit/Lowering.cpp
+++ b/js/src/jit/Lowering.cpp
@@ -4568,6 +4568,18 @@ LIRGenerator::visitCheckReturn(MCheckReturn* ins)
     redefine(ins, retVal);
 }
 
+void
+LIRGenerator::visitCheckIsObj(MCheckIsObj* ins)
+{
+    MDefinition* checkVal = ins->checkValue();
+    MOZ_ASSERT(checkVal->type() == MIRType::Value);
+
+    LCheckIsObj* lir = new(alloc()) LCheckIsObj(useBoxAtStart(checkVal));
+    redefine(ins, checkVal);
+    add(lir, ins);
+    assignSafepoint(lir, ins);
+}
+
 void
 LIRGenerator::visitCheckObjCoercible(MCheckObjCoercible* ins)
 {
diff --git a/js/src/jit/Lowering.h b/js/src/jit/Lowering.h
index 9b8ab3ce8870..5e6207ee5972 100644
--- a/js/src/jit/Lowering.h
+++ b/js/src/jit/Lowering.h
@@ -317,6 +317,7 @@ class LIRGenerator : public LIRGeneratorSpecific
     void visitAtomicIsLockFree(MAtomicIsLockFree* ins);
     void visitGuardSharedTypedArray(MGuardSharedTypedArray* ins);
     void visitCheckReturn(MCheckReturn* ins);
+    void visitCheckIsObj(MCheckIsObj* ins);
     void visitCheckObjCoercible(MCheckObjCoercible* ins);
     void visitDebugCheckSelfHosted(MDebugCheckSelfHosted* ins);
 };
diff --git a/js/src/jit/MIR.h b/js/src/jit/MIR.h
index 0608013d8983..a0c3c3e8cd04 100644
--- a/js/src/jit/MIR.h
+++ b/js/src/jit/MIR.h
@@ -13050,6 +13050,32 @@ class MDebugger : public MNullaryInstruction
     TRIVIAL_NEW_WRAPPERS
 };
 
+class MCheckIsObj
+  : public MUnaryInstruction,
+    public BoxInputsPolicy::Data
+{
+    uint8_t checkKind_;
+
+    explicit MCheckIsObj(MDefinition* toCheck, uint8_t checkKind)
+      : MUnaryInstruction(toCheck), checkKind_(checkKind)
+    {
+        setResultType(MIRType::Value);
+        setResultTypeSet(toCheck->resultTypeSet());
+        setGuard();
+    }
+
+  public:
+    INSTRUCTION_HEADER(CheckIsObj)
+    TRIVIAL_NEW_WRAPPERS
+    NAMED_OPERANDS((0, checkValue))
+
+    uint8_t checkKind() const { return checkKind_; }
+
+    AliasSet getAliasSet() const override {
+        return AliasSet::None();
+    }
+};
+
 class MCheckObjCoercible
   : public MUnaryInstruction,
     public BoxInputsPolicy::Data
@@ -13066,7 +13092,6 @@ class MCheckObjCoercible
     INSTRUCTION_HEADER(CheckObjCoercible)
     TRIVIAL_NEW_WRAPPERS
     NAMED_OPERANDS((0, checkValue))
-
 };
 
 class MDebugCheckSelfHosted
diff --git a/js/src/jit/MOpcodes.h b/js/src/jit/MOpcodes.h
index 6fb1c31d70d3..76fae5cada4d 100644
--- a/js/src/jit/MOpcodes.h
+++ b/js/src/jit/MOpcodes.h
@@ -302,6 +302,7 @@ namespace jit {
     _(NewTarget)                                                            \
     _(ArrowNewTarget)                                                       \
     _(CheckReturn)                                                          \
+    _(CheckIsObj)                                                             \
     _(CheckObjCoercible)                                                    \
     _(DebugCheckSelfHosted)
 
diff --git a/js/src/jit/shared/LIR-shared.h b/js/src/jit/shared/LIR-shared.h
index c60b58c639c8..b942e7c4a097 100644
--- a/js/src/jit/shared/LIR-shared.h
+++ b/js/src/jit/shared/LIR-shared.h
@@ -8696,6 +8696,22 @@ class LCheckReturn : public LCallInstructionHelper<BOX_PIECES, 2 * BOX_PIECES, 0
     static const size_t ThisValue = BOX_PIECES;
 };
 
+class LCheckIsObj : public LInstructionHelper<BOX_PIECES, BOX_PIECES, 0>
+{
+  public:
+    LIR_HEADER(CheckIsObj)
+
+    static const size_t CheckValue = 0;
+
+    explicit LCheckIsObj(const LBoxAllocation& value) {
+        setBoxOperand(CheckValue, value);
+    }
+
+    MCheckIsObj* mir() const {
+        return mir_->toCheckIsObj();
+    }
+};
+
 class LCheckObjCoercible : public LCallInstructionHelper<BOX_PIECES, BOX_PIECES, 0>
 {
   public:
diff --git a/js/src/jit/shared/LOpcodes-shared.h b/js/src/jit/shared/LOpcodes-shared.h
index fffaa2df194d..2a7794d8aaa6 100644
--- a/js/src/jit/shared/LOpcodes-shared.h
+++ b/js/src/jit/shared/LOpcodes-shared.h
@@ -427,6 +427,7 @@
     _(NewTarget)                    \
     _(ArrowNewTarget)               \
     _(CheckReturn)                  \
+    _(CheckIsObj)                   \
     _(CheckObjCoercible)            \
     _(DebugCheckSelfHosted)