diff --git a/include/swift/SIL/SILInstruction.h b/include/swift/SIL/SILInstruction.h
index 3e525237b5c..0e60d5c711d 100644
--- a/include/swift/SIL/SILInstruction.h
+++ b/include/swift/SIL/SILInstruction.h
@@ -52,8 +52,7 @@ enum class SILInstructionMemoryBehavior {
   ///        result/users represent its effect.
   MayHaveSideEffects,
   /// \brief The instruction may write to memory.
-  MayWrite,
-  MayWriteAndHaveSideEffects
+  MayWrite
 };
 
 enum IsTake_t { IsNotTake, IsTake };
diff --git a/include/swift/SIL/SILNodes.def b/include/swift/SIL/SILNodes.def
index 00d5fbbbfa2..49f70f35ba0 100644
--- a/include/swift/SIL/SILNodes.def
+++ b/include/swift/SIL/SILNodes.def
@@ -140,7 +140,7 @@ ABSTRACT_VALUE(SILInstruction, ValueBase)
   // Protocol and Protocol Composition Types
   INST(InitExistentialInst, SILInstruction, MayWrite)
   INST(UpcastExistentialInst, SILInstruction, MayWrite)
-  INST(DeinitExistentialInst, SILInstruction, MayWriteAndHaveSideEffects)
+  INST(DeinitExistentialInst, SILInstruction, MayHaveSideEffects)
   INST(ProjectExistentialInst, SILInstruction, None)
   INST(InitExistentialRefInst, SILInstruction, None)
   INST(UpcastExistentialRefInst, SILInstruction, None)
diff --git a/lib/SIL/SILInstruction.cpp b/lib/SIL/SILInstruction.cpp
index 55c104fe17c..640efb39a0f 100644
--- a/lib/SIL/SILInstruction.cpp
+++ b/lib/SIL/SILInstruction.cpp
@@ -201,11 +201,9 @@ SILInstructionMemoryBehavior SILInstruction::getMemoryBehavior() const {
 
 bool SILInstruction::mayHaveSideEffects() const {
   SILInstructionMemoryBehavior B = getMemoryBehavior();
-  if (B == SILInstructionMemoryBehavior::MayWrite ||
-      B == SILInstructionMemoryBehavior::MayHaveSideEffects ||
-      B == SILInstructionMemoryBehavior::MayWriteAndHaveSideEffects)
-    return true;
-  return false;
+
+  return B == SILInstructionMemoryBehavior::MayWrite ||
+    B == SILInstructionMemoryBehavior::MayHaveSideEffects;
 }
 
 //===----------------------------------------------------------------------===//