diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 611748ad3b7015..09c243ada305d3 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -1660,13 +1660,14 @@ void AArch64FrameLowering::emitPrologue(MachineFunction &MF,
           .setMIFlags(MachineInstr::FrameSetup);
     }
 
+    const char* ChkStk = Subtarget.getChkStkName();
     switch (MF.getTarget().getCodeModel()) {
     case CodeModel::Tiny:
     case CodeModel::Small:
     case CodeModel::Medium:
     case CodeModel::Kernel:
       BuildMI(MBB, MBBI, DL, TII->get(AArch64::BL))
-          .addExternalSymbol("__chkstk")
+          .addExternalSymbol(ChkStk)
           .addReg(AArch64::X15, RegState::Implicit)
           .addReg(AArch64::X16, RegState::Implicit | RegState::Define | RegState::Dead)
           .addReg(AArch64::X17, RegState::Implicit | RegState::Define | RegState::Dead)
@@ -1681,8 +1682,8 @@ void AArch64FrameLowering::emitPrologue(MachineFunction &MF,
     case CodeModel::Large:
       BuildMI(MBB, MBBI, DL, TII->get(AArch64::MOVaddrEXT))
           .addReg(AArch64::X16, RegState::Define)
-          .addExternalSymbol("__chkstk")
-          .addExternalSymbol("__chkstk")
+          .addExternalSymbol(ChkStk)
+          .addExternalSymbol(ChkStk)
           .setMIFlags(MachineInstr::FrameSetup);
       if (NeedsWinCFI) {
         HasWinCFI = true;
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index b5d8d3d6b4ef2e..67a5f88e1408e9 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -12492,7 +12492,8 @@ SDValue AArch64TargetLowering::LowerWindowsDYNAMIC_STACKALLOC(
     SDValue Op, SDValue Chain, SDValue &Size, SelectionDAG &DAG) const {
   SDLoc dl(Op);
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
-  SDValue Callee = DAG.getTargetExternalSymbol("__chkstk", PtrVT, 0);
+  SDValue Callee = DAG.getTargetExternalSymbol(Subtarget->getChkStkName(),
+                                               PtrVT, 0);
 
   const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
   const uint32_t *Mask = TRI->getWindowsStackProbePreservedMask();
@@ -20965,8 +20966,8 @@ void AArch64TargetLowering::insertSSPDeclarations(Module &M) const {
 
     // MSVC CRT has a function to validate security cookie.
     FunctionCallee SecurityCheckCookie = M.getOrInsertFunction(
-        "__security_check_cookie", Type::getVoidTy(M.getContext()),
-        Type::getInt8PtrTy(M.getContext()));
+        Subtarget->getSecurityCheckCookieName(),
+        Type::getVoidTy(M.getContext()), Type::getInt8PtrTy(M.getContext()));
     if (Function *F = dyn_cast<Function>(SecurityCheckCookie.getCallee())) {
       F->setCallingConv(CallingConv::Win64);
       F->addParamAttr(0, Attribute::AttrKind::InReg);
@@ -20986,7 +20987,7 @@ Value *AArch64TargetLowering::getSDagStackGuard(const Module &M) const {
 Function *AArch64TargetLowering::getSSPStackGuardCheck(const Module &M) const {
   // MSVC CRT has a function to validate security cookie.
   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment())
-    return M.getFunction("__security_check_cookie");
+    return M.getFunction(Subtarget->getSecurityCheckCookieName());
   return TargetLowering::getSSPStackGuardCheck(M);
 }
 
diff --git a/llvm/lib/Target/AArch64/AArch64Subtarget.h b/llvm/lib/Target/AArch64/AArch64Subtarget.h
index 31315953be3b9b..7296e144ced152 100644
--- a/llvm/lib/Target/AArch64/AArch64Subtarget.h
+++ b/llvm/lib/Target/AArch64/AArch64Subtarget.h
@@ -353,6 +353,19 @@ class AArch64Subtarget final : public AArch64GenSubtargetInfo {
   }
 
   unsigned getVScaleForTuning() const { return VScaleForTuning; }
+
+  const char* getChkStkName() const {
+    if (isWindowsArm64EC())
+      return "__chkstk_arm64ec";
+    return "__chkstk";
+  }
+
+  const char* getSecurityCheckCookieName() const {
+    if (isWindowsArm64EC())
+      return "__security_check_cookie_arm64ec";
+    return "__security_check_cookie";
+  }
+
 };
 } // End llvm namespace
 
diff --git a/llvm/test/CodeGen/AArch64/stack-protector-target.ll b/llvm/test/CodeGen/AArch64/stack-protector-target.ll
index 9d420e8db3e9ff..dc0a288d89186a 100644
--- a/llvm/test/CodeGen/AArch64/stack-protector-target.ll
+++ b/llvm/test/CodeGen/AArch64/stack-protector-target.ll
@@ -3,6 +3,7 @@
 ; RUN: llc -mtriple=aarch64-fuchsia < %s -o - | FileCheck --check-prefixes=FUCHSIA-AARCH64-COMMON,FUCHSIA-AARCH64-USER %s
 ; RUN: llc -mtriple=aarch64-fuchsia -mattr=+tpidr-el1 < %s -o - | FileCheck --check-prefixes=FUCHSIA-AARCH64-COMMON,FUCHSIA-AARCH64-KERNEL %s
 ; RUN: llc -mtriple=aarch64-windows < %s -o - | FileCheck --check-prefix=WINDOWS-AARCH64 %s
+; RUN: llc -mtriple=arm64ec-windows-msvc < %s -o - | FileCheck --check-prefix=WINDOWS-ARM64EC %s
 
 define void @_Z1fv() sspreq {
 entry:
@@ -35,3 +36,10 @@ declare void @_Z7CapturePi(i32*)
 ; WINDOWS-AARCH64: bl  _Z7CapturePi
 ; WINDOWS-AARCH64: ldr x0, [sp, #8]
 ; WINDOWS-AARCH64: bl  __security_check_cookie
+
+; WINDOWS-ARM64EC: adrp x8, __security_cookie
+; WINDOWS-ARM64EC: ldr x8, [x8, :lo12:__security_cookie]
+; WINDOWS-ARM64EC: str x8, [sp, #8]
+; WINDOWS-ARM64EC: bl  _Z7CapturePi
+; WINDOWS-ARM64EC: ldr x0, [sp, #8]
+; WINDOWS-ARM64EC: bl  __security_check_cookie_arm64ec
diff --git a/llvm/test/CodeGen/AArch64/win-alloca.ll b/llvm/test/CodeGen/AArch64/win-alloca.ll
index 9c34cabbb5471a..e4d52ca9900183 100644
--- a/llvm/test/CodeGen/AArch64/win-alloca.ll
+++ b/llvm/test/CodeGen/AArch64/win-alloca.ll
@@ -1,5 +1,6 @@
 ; RUN: llc -mtriple aarch64-windows -verify-machineinstrs -filetype asm -o - %s | FileCheck %s -check-prefixes=CHECK,CHECK-OPT
 ; RUN: llc -mtriple aarch64-windows -verify-machineinstrs -filetype asm -o - %s -O0 | FileCheck %s
+; RUN: llc -mtriple arm64ec-windows-msvc -verify-machineinstrs -filetype asm -o - %s | FileCheck -check-prefix=CHECK-ARM64EC %s
 
 define void @func(i64 %a) {
 entry:
@@ -20,3 +21,4 @@ declare void @func2(i8*)
 ; CHECK-OPT: sub [[REG3:x[0-9]+]], sp, x15, lsl #4
 ; CHECK-OPT: mov sp, [[REG3]]
 ; CHECK: bl func2
+; CHECK-ARM64EC: bl __chkstk_arm64ec