diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index d9bf62c2bbb04..76e5007357e4d 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -1296,13 +1296,6 @@ ItaniumRecordLayoutBuilder::LayoutBase(const BaseSubobjectInfo *Base) {
     bool Allowed = EmptySubobjects->CanPlaceBaseAtOffset(Base, Offset);
     (void)Allowed;
     assert(Allowed && "Base subobject externally placed at overlapping offset");
-
-    if (InferAlignment && Offset < getDataSize().alignTo(AlignTo)) {
-      // The externally-supplied base offset is before the base offset we
-      // computed. Assume that the structure is packed.
-      Alignment = CharUnits::One();
-      InferAlignment = false;
-    }
   }
 
   if (!Base->Class->isEmpty()) {
@@ -2255,9 +2248,27 @@ ItaniumRecordLayoutBuilder::updateExternalFieldOffset(const FieldDecl *Field,
                                                       uint64_t ComputedOffset) {
   uint64_t ExternalFieldOffset = External.getExternalFieldOffset(Field);
 
-  if (InferAlignment && ExternalFieldOffset < ComputedOffset) {
-    // The externally-supplied field offset is before the field offset we
-    // computed. Assume that the structure is packed.
+  // DWARF doesn't tell us whether a structure was declared as packed.
+  // So we try to figure out if the supplied Field is at a packed offset
+  // (i.e., the externally-supplied offset is less than the layout builder
+  // expected).
+  //
+  // There are cases where fields are placed at overlapping offsets (e.g.,
+  // as a result of [[no_unique_address]]). In those cases we don't want
+  // to incorrectly deduce that they are placed at packed offsets. Hence,
+  // ignore empty fields (which are the only fields that can overlap).
+  //
+  // FIXME: emit enough information in DWARF to get rid of InferAlignment.
+  //
+  CXXRecordDecl *CXX = nullptr;
+  if (auto *RT = dyn_cast<RecordType>(Field->getType()))
+    CXX = RT->getAsCXXRecordDecl();
+
+  const bool assume_packed = ExternalFieldOffset > 0 &&
+                             ExternalFieldOffset < ComputedOffset &&
+                             !(CXX && CXX->isEmpty());
+
+  if (InferAlignment && assume_packed) {
     Alignment = CharUnits::One();
     PreferredAlignment = CharUnits::One();
     InferAlignment = false;
diff --git a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-packed-alignment.cpp b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-packed-alignment.cpp
new file mode 100644
index 0000000000000..e47dab45ff7b7
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-packed-alignment.cpp
@@ -0,0 +1,23 @@
+// RUN: %clangxx_host -gdwarf -o %t %s
+// RUN: %lldb %t \
+// RUN:   -o "expr alignof(PackedNUA)" \
+// RUN:   -o "expr sizeof(PackedNUA)" \
+// RUN:   -o exit | FileCheck %s
+
+struct Empty {};
+struct __attribute((packed)) PackedNUA {
+  [[no_unique_address]] Empty a, b, c, d;
+  char x;
+  int y;
+};
+static_assert(alignof(PackedNUA) == 1);
+static_assert(sizeof(PackedNUA) == 5);
+
+PackedNUA packed;
+
+// CHECK:      (lldb) expr alignof(PackedNUA)
+// CHECK-NEXT: ${{.*}} = 1
+// CHECK:      (lldb) expr sizeof(PackedNUA)
+// CHECK-NEXT: ${{.*}} = 5
+
+int main() { PackedNUA d; }
diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-alignment.cpp b/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-alignment.cpp
index e198bf0cafeaa..cf499388c56d5 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-alignment.cpp
+++ b/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-alignment.cpp
@@ -1,5 +1,3 @@
-// XFAIL: *
-
 // RUN: %clang --target=x86_64-apple-macosx -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "expr alignof(OverlappingFields)" \
diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-base-alignment.cpp b/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-base-alignment.cpp
index c4bcfc473277f..2cf1eb30d7a26 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-base-alignment.cpp
+++ b/lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-base-alignment.cpp
@@ -1,5 +1,3 @@
-// XFAIL: *
-
 // RUN: %clang --target=x86_64-apple-macosx -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "expr alignof(OverlappingDerived)" \