diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index a22d03e20be..0e5fd1f6e0c 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5863,6 +5863,30 @@ validateInstruction(MCInst &Inst,
       return Error(Operands[Op]->getStartLoc(), "branch target out of range");
     break;
   }
+  case ARM::MOVi16:
+  case ARM::t2MOVi16:
+  case ARM::t2MOVTi16:
+    {
+    // We want to avoid misleadingly allowing something like "mov r0, <symbol>"
+    // especially when we turn it into a movw and the expression <symbol> does
+    // not have a :lower16: or :upper16 as part of the expression.  We don't
+    // want the behavior of silently truncating, which can be unexpected and
+    // lead to bugs that are difficult to find since this is an easy mistake
+    // to make.
+    int i = (Operands[3]->isImm()) ? 3 : 4;
+    ARMOperand *Op = static_cast<ARMOperand*>(Operands[i]);
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Op->getImm());
+    if (CE) break;
+    const MCExpr *E = dyn_cast<MCExpr>(Op->getImm());
+    if (!E) break;
+    const ARMMCExpr *ARM16Expr = dyn_cast<ARMMCExpr>(E);
+    if (!ARM16Expr || (ARM16Expr->getKind() != ARMMCExpr::VK_ARM_HI16 &&
+                       ARM16Expr->getKind() != ARMMCExpr::VK_ARM_LO16)) {
+      return Error(Op->getStartLoc(),
+	     "immediate expression for mov requires :lower16: or :upper16");
+      break;
+    }
+    }
   }
 
   return false;
diff --git a/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp b/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
index 5564e0a8c1a..c0857e128ec 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
+++ b/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
@@ -1040,12 +1040,12 @@ ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
     return 0;
   }
   // If the expression doesn't have :upper16: or :lower16: on it,
-  // it's just a plain immediate expression, and those evaluate to
+  // it's just a plain immediate expression, previously those evaluated to
   // the lower 16 bits of the expression regardless of whether
-  // we have a movt or a movw.
-  Kind = MCFixupKind(isThumb2(STI) ? ARM::fixup_t2_movw_lo16
-                                   : ARM::fixup_arm_movw_lo16);
-  Fixups.push_back(MCFixup::Create(0, E, Kind, MI.getLoc()));
+  // we have a movt or a movw, but that led to misleadingly results.
+  // This is now disallowed in the the AsmParser in validateInstruction()
+  // so this should never happen.
+  assert(0 && "expression without :upper16: or :lower16:");
   return 0;
 }
 
diff --git a/test/MC/ARM/arm_fixups.s b/test/MC/ARM/arm_fixups.s
index bd6906bae77..1f56e128524 100644
--- a/test/MC/ARM/arm_fixups.s
+++ b/test/MC/ARM/arm_fixups.s
@@ -26,9 +26,9 @@
 @ CHECK-BE: movt	r9, :upper16:_foo       @ encoding: [0xe3,0b0100AAAA,0x90'A',A]
 @ CHECK-BE: @   fixup A - offset: 0, value: _foo, kind: fixup_arm_movt_hi16
 
-    mov r2, fred
+    mov r2, :lower16:fred
 
-@ CHECK: movw  r2, fred                 @ encoding: [A,0x20'A',0b0000AAAA,0xe3]
+@ CHECK: movw  r2, :lower16:fred                 @ encoding: [A,0x20'A',0b0000AAAA,0xe3]
 @ CHECK: @   fixup A - offset: 0, value: fred, kind: fixup_arm_movw_lo16
-@ CHECK-BE: movw  r2, fred                 @ encoding: [0xe3,0b0000AAAA,0x20'A',A]
+@ CHECK-BE: movw  r2, :lower16:fred                 @ encoding: [0xe3,0b0000AAAA,0x20'A',A]
 @ CHECK-BE: @   fixup A - offset: 0, value: fred, kind: fixup_arm_movw_lo16
diff --git a/test/MC/ARM/complex-operands.s b/test/MC/ARM/complex-operands.s
index 2a721c4e101..72f8f88d2aa 100644
--- a/test/MC/ARM/complex-operands.s
+++ b/test/MC/ARM/complex-operands.s
@@ -21,20 +21,20 @@ return:
 	.global arm_function
 	.type arm_function,%function
 arm_function:
-	mov r0, #(.L_table_end - .L_table_begin) >> 2
+	mov r0, #:lower16:((.L_table_end - .L_table_begin) >> 2)
 	blx return
 
 @ CHECK-LABEL: arm_function
-@ CHECK:  	movw r0, #(.L_table_end-.L_table_begin)>>2
+@ CHECK:  	movw r0, :lower16:((.L_table_end-.L_table_begin)>>2)
 @ CHECK:  	blx return
 
 	.global thumb_function
 	.type thumb_function,%function
 thumb_function:
-	mov r0, #(.L_table_end - .L_table_begin) >> 2
+	mov r0, #:lower16:((.L_table_end - .L_table_begin) >> 2)
 	blx return
 
 @ CHECK-LABEL: thumb_function
-@ CHECK:  	movw r0, #(.L_table_end-.L_table_begin)>>2
+@ CHECK:  	movw r0, :lower16:((.L_table_end-.L_table_begin)>>2)
 @ CHECK:  	blx return
 
diff --git a/test/MC/ARM/diagnostics.s b/test/MC/ARM/diagnostics.s
index 3c26f6d645c..62d7daea28a 100644
--- a/test/MC/ARM/diagnostics.s
+++ b/test/MC/ARM/diagnostics.s
@@ -465,3 +465,11 @@
         ldm sp!, {r0}^
 @ CHECK-ERRORS: error: system STM cannot have writeback register
 @ CHECK-ERRORS: error: writeback register only allowed on system LDM if PC in register-list
+
+foo2:
+        mov r0, foo2
+        movw r0, foo2
+@ CHECK-ERRORS: error: immediate expression for mov requires :lower16: or :upper16
+@ CHECK-ERRORS:                 ^
+@ CHECK-ERRORS: error: immediate expression for mov requires :lower16: or :upper16
+@ CHECK-ERRORS:                  ^
diff --git a/test/MC/ARM/thumb2-diagnostics.s b/test/MC/ARM/thumb2-diagnostics.s
index 6ac2db02cca..bb96db05b92 100644
--- a/test/MC/ARM/thumb2-diagnostics.s
+++ b/test/MC/ARM/thumb2-diagnostics.s
@@ -70,3 +70,14 @@
 @ CHECK-ERRORS: error: branch target out of range
 @ CHECK-ERRORS: error: branch target out of range
 @ CHECK-ERRORS: error: branch target out of range
+
+foo2:
+        mov r0, foo2
+        movw r0, foo2
+        movt r0, foo2
+@ CHECK-ERRORS: error: immediate expression for mov requires :lower16: or :upper16
+@ CHECK-ERRORS:                 ^
+@ CHECK-ERRORS: error: immediate expression for mov requires :lower16: or :upper16
+@ CHECK-ERRORS:                  ^
+@ CHECK-ERRORS: error: immediate expression for mov requires :lower16: or :upper16
+@ CHECK-ERRORS:                  ^