diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.cpp
--- a/lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.cpp
@@ -45,10 +45,12 @@
     break;
   case LF_UNION:
     llvm::cantFail(TypeDeserializer::deserializeAs<UnionRecord>(cvt, m_cvr.ur));
+     m_layout.bit_size = m_cvr.ur.getSize() * 8;
     break;
   case LF_CLASS:
   case LF_STRUCTURE:
     llvm::cantFail(TypeDeserializer::deserializeAs<ClassRecord>(cvt, m_cvr.cr));
+     m_layout.bit_size = m_cvr.cr.getSize() * 8;
     break;
   default:
     llvm_unreachable("unreachable!");
diff --git a/lldb/test/Shell/SymbolFile/NativePDB/packed_class_layout.cpp b/lldb/test/Shell/SymbolFile/NativePDB/packed_class_layout.cpp
new file mode 100644
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/NativePDB/packed_class_layout.cpp
@@ -0,0 +1,34 @@
+// clang-format off
+// REQUIRES: lld, x86
+
+// Make sure class layout is correct.
+// RUN: %clang_cl --target=x86_64-windows-msvc -Od -Z7 -c /Fo%t.obj -- %s
+// RUN: lld-link -debug:full -nodefaultlib -entry:main %t.obj -out:%t.exe -pdb:%t.pdb
+// RUN: env LLDB_USE_NATIVE_PDB_READER=1 %lldb -f %t.exe \
+// RUN:     -o "expr a" -o "expr u.c" -o "expr u.i" -o "exit" | FileCheck %s
+
+// CHECK:      (lldb) expr a
+// CHECK-NEXT: (A) $0 = (d1 = 'a', d2 = 1, d3 = 2, d4 = 'b')
+// CHECK-NEXT: (lldb) expr u.c
+// CHECK-NEXT: (char[3]) $1 = "a"
+// CHECK-NEXT: (lldb) expr u.i
+// CHECK-NEXT: (int) $2 = 97
+
+struct __attribute__((packed, aligned(1))) A {
+  char d1;
+  int d2;
+  int d3;
+  char d4;
+};
+
+union __attribute__((packed, aligned(1))) U {
+  char c[2];
+  int i;
+};
+
+A a = {'a', 1, 2, 'b'};
+U u = {"a"};
+
+int main() {
+  return 0;
+}