diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -10309,11 +10309,14 @@
         !HasWideQualifier) {
       // The operands aren't the same for tMOV[S]r... (no cc_out)
       MCInst TmpInst;
-      TmpInst.setOpcode(Inst.getOperand(4).getReg() ? ARM::tMOVSr : ARM::tMOVr);
+      unsigned Op = Inst.getOperand(4).getReg() ? ARM::tMOVSr : ARM::tMOVr;
+      TmpInst.setOpcode(Op);
       TmpInst.addOperand(Inst.getOperand(0));
       TmpInst.addOperand(Inst.getOperand(1));
-      TmpInst.addOperand(Inst.getOperand(2));
-      TmpInst.addOperand(Inst.getOperand(3));
+      if (Op == ARM::tMOVr) {
+        TmpInst.addOperand(Inst.getOperand(2));
+        TmpInst.addOperand(Inst.getOperand(3));
+      }
       Inst = TmpInst;
       return true;
     }
diff --git a/llvm/test/MC/ARM/tMOVSr.s b/llvm/test/MC/ARM/tMOVSr.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/ARM/tMOVSr.s
@@ -0,0 +1,6 @@
+@ REQUIRES: asserts
+@ RUN: llvm-mc --triple=thumbv8 --debug %s 2>&1 | FileCheck %s --match-full-lines
+
+@ CHECK: Changed to: <MCInst #{{[0-9]+}} tMOVSr <MCOperand Reg:{{[0-9]+}}> <MCOperand Reg:{{[0-9]+}}>>
+.text
+  movs r2, r3