diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index b62f6e20496..2f608b26acc 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -571,6 +571,14 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) {
 Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
                                        ICmpInst::Predicate Cond,
                                        Instruction &I) {
+  // Don't transform signed compares of GEPs into index compares. Even if the
+  // GEP is inbounds, the final add of the base pointer can have signed overflow
+  // and would change the result of the icmp.
+  // e.g. "&foo[0] <s &foo[1]" can't be folded to "true" because "foo" could be
+  // the minimum signed value for the pointer type.
+  if (ICmpInst::isSigned(Cond))
+    return 0;
+
   // Look through bitcasts.
   if (BitCastInst *BCI = dyn_cast<BitCastInst>(RHS))
     RHS = BCI->getOperand(0);
diff --git a/test/Transforms/InstCombine/icmp.ll b/test/Transforms/InstCombine/icmp.ll
index 8c4871942cb..dabb0f3adfe 100644
--- a/test/Transforms/InstCombine/icmp.ll
+++ b/test/Transforms/InstCombine/icmp.ll
@@ -628,3 +628,14 @@ define i1 @test61(i8* %foo, i64 %i, i64 %j) {
 ; CHECK: icmp ult i8* %cast1, %gep2
 ; CHECK-NEXT: ret i1
 }
+
+define i1 @test62(i8* %a) {
+  %arrayidx1 = getelementptr inbounds i8* %a, i64 1
+  %arrayidx2 = getelementptr inbounds i8* %a, i64 10
+  %cmp = icmp slt i8* %arrayidx1, %arrayidx2
+  ret i1 %cmp
+; Don't turn a signed cmp of GEPs into an index compare.
+; CHECK: @test62
+; CHECK: %cmp = icmp slt i8* %arrayidx1, %arrayidx2
+; CHECK-NEXT: ret i1 %cmp
+}