diff --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -1026,7 +1026,7 @@
 /// until we reach a value that dominates InsertPos.
 bool SCEVExpander::hoistIVInc(Instruction *IncV, Instruction *InsertPos,
                               bool RecomputePoisonFlags) {
-  if (SE.DT.dominates(IncV, InsertPos))
+  if (SE.DT.dominates(IncV, InsertPos) && !RecomputePoisonFlags)
       return true;
 
   // InsertPos must itself dominate IncV so that IncV's new position satisfies
diff --git a/llvm/test/Transforms/IndVarSimplify/iv-poison.ll b/llvm/test/Transforms/IndVarSimplify/iv-poison.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/iv-poison.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=indvars -S < %s | FileCheck %s
+
+define i2 @iv_hoist_nsw_poison(i2 %0) {
+; CHECK-LABEL: @iv_hoist_nsw_poison(
+; CHECK-NEXT:    br label [[TMP2:%.*]]
+; CHECK:       2:
+; CHECK-NEXT:    [[DOT07:%.*]] = phi i2 [ 1, [[TMP1:%.*]] ], [ [[TMP3:%.*]], [[TMP2]] ]
+; CHECK-NEXT:    [[TMP3]] = add nuw i2 [[DOT07]], 1
+; CHECK-NEXT:    [[DOTNOT_NOT:%.*]] = icmp ult i2 1, [[TMP0:%.*]]
+; CHECK-NEXT:    br i1 [[DOTNOT_NOT]], label [[COMMON_RET:%.*]], label [[TMP2]]
+; CHECK:       common.ret:
+; CHECK-NEXT:    [[DOTLCSSA:%.*]] = phi i2 [ [[TMP3]], [[TMP2]] ]
+; CHECK-NEXT:    ret i2 [[DOTLCSSA]]
+;
+  br label %2
+
+2:                                                ; preds = %2, %1
+  %.07 = phi i2 [ 1, %1 ], [ %3, %2 ]
+  %.0 = phi i2 [ 1, %1 ], [ %4, %2 ]
+  %3 = add nsw i2 %.07, 1
+  %4 = add i2 %.0, 1
+  %.not.not = icmp ult i2 %.07, %0
+  br i1 %.not.not, label %common.ret, label %2
+
+common.ret:                                       ; preds = %2
+  ret i2 %4
+}