diff --git a/lib/IRGen/GenExistential.cpp b/lib/IRGen/GenExistential.cpp
index 5e0d4af15359d..8f5699184c495 100644
--- a/lib/IRGen/GenExistential.cpp
+++ b/lib/IRGen/GenExistential.cpp
@@ -168,7 +168,11 @@ namespace {
       const size_t count = pThis->NumStoredProtocols;
       const size_t size =
           Tail::template totalSizeToAlloc<const ProtocolDecl *>(count);
+#if defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309L
       ::operator delete(ptr, size);
+#else
+      ::operator delete(ptr);
+#endif
     }
 
     /// Returns the number of protocol witness tables directly carried
diff --git a/lib/IRGen/GenRecord.h b/lib/IRGen/GenRecord.h
index 65acff49edccf..0416cca7dd858 100644
--- a/lib/IRGen/GenRecord.h
+++ b/lib/IRGen/GenRecord.h
@@ -161,7 +161,11 @@ class RecordTypeInfoImpl : public Base,
     const auto *pThis = static_cast<RecordTypeInfoImpl *>(ptr);
     const size_t count = pThis->NumFields;
     const size_t size = Impl::template totalSizeToAlloc<FieldImpl>(count);
+#if defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309L
     ::operator delete(ptr, size);
+#else
+    ::operator delete(ptr);
+#endif
   }
 
   bool areFieldsABIAccessible() const {
diff --git a/lib/IRGen/ProtocolInfo.h b/lib/IRGen/ProtocolInfo.h
index 8c4180cb549c1..88d3b8199945f 100644
--- a/lib/IRGen/ProtocolInfo.h
+++ b/lib/IRGen/ProtocolInfo.h
@@ -234,7 +234,11 @@ class ProtocolInfo final :
     const auto *pThis = static_cast<ProtocolInfo *>(ptr);
     const size_t count = pThis->NumTableEntries;
     const size_t size = totalSizeToAlloc<WitnessTableEntry>(count);
+#if defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309L
     ::operator delete(ptr, size);
+#else
+    ::operator delete(ptr);
+#endif
   }
 
   /// The number of witness slots in a conformance to this protocol;