diff --git a/stdlib/public/RemoteInspection/TypeLowering.cpp b/stdlib/public/RemoteInspection/TypeLowering.cpp
index eb10a809c77e6..541c039f6141f 100644
--- a/stdlib/public/RemoteInspection/TypeLowering.cpp
+++ b/stdlib/public/RemoteInspection/TypeLowering.cpp
@@ -437,14 +437,26 @@ BitMask RecordTypeInfo::getSpareBits(TypeConverter &TC, bool &hasAddrOnly) const
     // Mask the rest of the fields as usual...
     break;
   }
-  case RecordKind::ClassExistential:
-    // Class existential is a data pointer that does expose spare bits
-    // ... so we can fall through ...
+  case RecordKind::ClassExistential: {
+    // First pointer in a Class Existential is the class pointer
+    // itself, which can be tagged or have other mysteries on 64-bit, so
+    // it exposes no spare bits from the first word there...
+    auto pointerBytes = TC.targetPointerSize();
+    if (pointerBytes == 8) {
+      auto zeroPointerSizedMask = BitMask::zeroMask(pointerBytes);
+      mask.andMask(zeroPointerSizedMask, 0);
+    }
+    // Otherwise, it's the same as an Existential Metatype
+    SWIFT_FALLTHROUGH;
+  }
   case RecordKind::ExistentialMetatype: {
-    // Initial metadata pointer has spare bits
+    // All the pointers in an Existential Metatype expose spare bits...
+    auto pointerBytes = TC.targetPointerSize();
     auto mpePointerSpareBits = TC.getBuilder().getMultiPayloadEnumPointerMask();
-    mask.andMask(mpePointerSpareBits, 0);
-    mask.keepOnlyLeastSignificantBytes(TC.targetPointerSize());
+    auto mpePointerSpareBitMask = BitMask(pointerBytes, mpePointerSpareBits);
+    for (int offset = 0; offset < (int)getSize(); offset += pointerBytes) {
+      mask.andMask(mpePointerSpareBitMask, offset);
+    }
     return mask;
   }
   case RecordKind::ErrorExistential:
diff --git a/validation-test/Reflection/reflect_Enum_values10.swift b/validation-test/Reflection/reflect_Enum_values10.swift
index 728c79b67a05d..c9c54addaa68f 100644
--- a/validation-test/Reflection/reflect_Enum_values10.swift
+++ b/validation-test/Reflection/reflect_Enum_values10.swift
@@ -10,9 +10,6 @@
 // UNSUPPORTED: use_os_stdlib
 // UNSUPPORTED: asan
 
-// This is broken on ARM64_32, disable it temporarily until we can fix it. rdar://137351613
-// UNSUPPORTED: CPU=arm64_32
-
 import SwiftReflectionTest
 
 protocol P : AnyObject {
@@ -24,7 +21,8 @@ class C : P {
   init() { a = 0; b = 0; }
 }
 
-// MemoryLayout<B>.size == 8
+// On 64-bit: MemoryLayout<B>.size == 8
+// On 32-bit: MemoryLayout<B>.size == 4
 enum B {
 case a(C)
 case b(C)
@@ -44,8 +42,8 @@ reflect(enumValue: B.b(C()))
 // CHECKALL-NEXT: (enum reflect_Enum_values10.B)
 // CHECKALL-NEXT: Value: .b(_)
 
-// MemoryLayout<Q>.size == 16
-// MemoryLayout<P>.size == 16
+// On 64-bit: MemoryLayout<Q>.size == MemoryLayout<P>.size == 16
+// On 32-bit: MemoryLayout<Q>.size == MemoryLayout<P>.size == 8
 enum Q {
 case a(P)
 case b(P)
@@ -65,6 +63,114 @@ reflect(enumValue: Q.b(C()))
 // CHECKALL-NEXT: (enum reflect_Enum_values10.Q)
 // CHECKALL-NEXT: Value: .b(_)
 
+enum B1 {
+case a(C)
+case b
+}
+
+reflect(enumValue: B1.a(C()))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.B1)
+// CHECKALL-NEXT: Value: .a(_)
+
+reflect(enumValue: B1.b)
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.B1)
+// CHECKALL-NEXT: Value: .b
+
+enum Q1 {
+case a(P)
+case b
+}
+
+reflect(enumValue: Q1.a(C()))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.Q1)
+// CHECKALL-NEXT: Value: .a(_)
+
+reflect(enumValue: Q1.b)
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.Q1)
+// CHECKALL-NEXT: Value: .b
+
+enum B2 {
+case a(C)
+case b(C)
+case c(C)
+case d(C)
+case e(C)
+}
+
+reflect(enumValue: B2.a(C()))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.B2)
+// CHECKALL-NEXT: Value: .a(_)
+
+reflect(enumValue: B2.e(C()))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.B2)
+// CHECKALL-NEXT: Value: .e(_)
+
+// On 64-bit: MemoryLayout<Q>.size == MemoryLayout<P>.size == 16
+// On 32-bit: MemoryLayout<Q>.size == MemoryLayout<P>.size == 8
+enum Q2 {
+case a(P)
+case b(P)
+case c(P)
+case d(P)
+case e(P)
+}
+
+reflect(enumValue: Q2.a(C()))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.Q2)
+// CHECKALL-NEXT: Value: .a(_)
+
+reflect(enumValue: Q2.e(C()))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (enum reflect_Enum_values10.Q2)
+// CHECKALL-NEXT: Value: .e(_)
+
+reflect(enumValue: Optional<Q2>.some(.a(C())))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (bound_generic_enum Swift.Optional
+// CHECKALL-NEXT:   (enum reflect_Enum_values10.Q2))
+// CHECKALL-NEXT: Value: .some(.a(_))
+
+reflect(enumValue: Optional<Q2>.some(.e(C())))
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (bound_generic_enum Swift.Optional
+// CHECKALL-NEXT:   (enum reflect_Enum_values10.Q2))
+// CHECKALL-NEXT: Value: .some(.e(_))
+
+reflect(enumValue: Optional<Q2>.none)
+
+// CHECKALL: Reflecting an enum value.
+// CHECKALL-NEXT: Type reference:
+// CHECKALL-NEXT: (bound_generic_enum Swift.Optional
+// CHECKALL-NEXT:   (enum reflect_Enum_values10.Q2))
+// CHECKALL-NEXT: Value: .none
+
 doneReflecting()
 
 // CHECKALL: Done.