diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 2fae489371d..6e0062ac44d 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -3284,7 +3284,8 @@ ARMAsmParser::OperandMatchResultTy ARMAsmParser::
 parseProcIFlagsOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
   SMLoc S = Parser.getTok().getLoc();
   const AsmToken &Tok = Parser.getTok();
-  assert(Tok.is(AsmToken::Identifier) && "Token is not an Identifier");
+  if (!Tok.is(AsmToken::Identifier)) 
+    return MatchOperand_NoMatch;
   StringRef IFlagsStr = Tok.getString();
 
   // An iflags string of "none" is interpreted to mean that none of the AIF
diff --git a/test/MC/ARM/diagnostics.s b/test/MC/ARM/diagnostics.s
index 7da79c31dc3..117c8514f3a 100644
--- a/test/MC/ARM/diagnostics.s
+++ b/test/MC/ARM/diagnostics.s
@@ -315,3 +315,9 @@
 @ CHECK-ERRORS: error: coprocessor option must be an immediate in range [0, 255]
 @ CHECK-ERRORS:         ldc2 p2, c8, [r1], { -1 }
 @ CHECK-ERRORS:                              ^
+
+        @ Bad CPS instruction format.
+        cps f,#1
+@ CHECK-ERRORS: error: invalid operand for instruction
+@ CHECK-ERRORS:         cps f,#1
+@ CHECK-ERRORS:               ^