diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -237,6 +237,8 @@
         DefaultDest->removePredecessor(ParentBB);
         i = SI->removeCase(i);
         e = SI->case_end();
+        // Removing this case may have made the condition constant.
+        CI = dyn_cast<ConstantInt>(SI->getCondition());
         Changed = true;
         continue;
       }
diff --git a/llvm/test/Transforms/SimplifyCFG/switch-simplify-crash2.ll b/llvm/test/Transforms/SimplifyCFG/switch-simplify-crash2.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyCFG/switch-simplify-crash2.ll
@@ -0,0 +1,47 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -O2 < %s | FileCheck %s
+
+define i8 @f(i1 %0) {
+; CHECK-LABEL: @f(
+; CHECK-NEXT:    br label [[DOTPEEL_BEGIN:%.*]]
+; CHECK:       .loopexit:
+; CHECK-NEXT:    br label [[DOTLOOPEXIT:%.*]]
+; CHECK:       .peel.begin:
+; CHECK-NEXT:    br i1 [[TMP0:%.*]], label [[DOTLOOPEXIT]], label [[DOTPEEL_BEGIN]]
+;
+  br label %6
+
+2:                                                ; preds = %8, %3
+  br i1 %0, label %8, label %6
+
+3:                                                ; preds = %6, %3
+  %.0 = phi i8 [ %.4, %6 ], [ 0, %3 ]
+  switch i8 %.0, label %5 [
+  i8 0, label %2
+  i8 1, label %3
+  ]
+
+4:                                                ; preds = %8, %5
+  %.1 = phi i8 [ %.2, %5 ], [ 1, %8 ]
+  br label %8
+
+5:                                                ; preds = %8, %7, %3
+  %.2 = phi i8 [ 0, %3 ], [ %.7, %7 ], [ 0, %8 ]
+  br label %4
+
+6:                                                ; preds = %2, %1
+  %.4 = phi i8 [ 0, %1 ], [ 1, %2 ]
+  br label %3
+
+7:                                                ; preds = %8
+  br label %5
+
+8:                                                ; preds = %8, %4, %2
+  %.7 = phi i8 [ %.1, %4 ], [ 0, %8 ], [ 2, %2 ]
+  switch i8 %.7, label %7 [
+  i8 0, label %5
+  i8 1, label %4
+  i8 4, label %8
+  i8 3, label %2
+  ]
+}