diff --git a/src/coreclr/jit/codegenarm64.cpp b/src/coreclr/jit/codegenarm64.cpp
index f5ac76f6c50067..5b680d4ce57702 100644
--- a/src/coreclr/jit/codegenarm64.cpp
+++ b/src/coreclr/jit/codegenarm64.cpp
@@ -2161,7 +2161,9 @@ void CodeGen::instGen_Set_Reg_To_Base_Plus_Imm(emitAttr       size,
     else
     {
         instGen_Set_Reg_To_Imm(size, dstReg, imm);
-        GetEmitter()->emitIns_R_R_R(INS_add, size, dstReg, dstReg, baseReg);
+        // baseReg might be SP, which must be reg2
+        // an "add R0, R1, SP" is not encodable
+        GetEmitter()->emitIns_R_R_R(INS_add, size, dstReg, baseReg, dstReg);
     }
 }