diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index b3df9261195..ce041884909 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -994,6 +994,10 @@ const SCEV *ScalarEvolution::getSignExtendExpr(const SCEV *Op,
   if (const SCEVSignExtendExpr *SS = dyn_cast<SCEVSignExtendExpr>(Op))
     return getSignExtendExpr(SS->getOperand(), Ty);
 
+  // sext(zext(x)) --> zext(x)
+  if (const SCEVZeroExtendExpr *SZ = dyn_cast<SCEVZeroExtendExpr>(Op))
+    return getZeroExtendExpr(SZ->getOperand(), Ty);
+
   // Before doing any expensive analysis, check to see if we've already
   // computed a SCEV for this Op and Ty.
   FoldingSetNodeID ID;
diff --git a/test/Analysis/ScalarEvolution/fold.ll b/test/Analysis/ScalarEvolution/fold.ll
new file mode 100644
index 00000000000..202ddd4169a
--- /dev/null
+++ b/test/Analysis/ScalarEvolution/fold.ll
@@ -0,0 +1,8 @@
+; RUN: opt -analyze -scalar-evolution %s -S | FileCheck %s
+
+define i16 @test(i8 %x) {
+  %A = zext i8 %x to i12
+  %B = sext i12 %A to i16
+; CHECK: zext i8 %x to i16
+  ret i16 %B
+}