diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 8215f3a4fdae..40a6b8e4c8e6 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2030,6 +2030,8 @@ let Predicates = [HasPAuthLR] in {
     //                              opcode2, opcode,   asm
     def AUTIASPPCr : SignAuthOneReg<0b00001, 0b100100, "autiasppcr">;
     def AUTIBSPPCr : SignAuthOneReg<0b00001, 0b100101, "autibsppcr">;
+  }
+  let Defs = [X17], Uses = [X15, X16, X17] in {
     //                                  opcode2, opcode,   asm
     def PACIA171615 : SignAuthFixedRegs<0b00001, 0b100010, "pacia171615">;
     def PACIB171615 : SignAuthFixedRegs<0b00001, 0b100011, "pacib171615">;