Index: lib/AST/ASTImporter.cpp
===================================================================
--- lib/AST/ASTImporter.cpp
+++ lib/AST/ASTImporter.cpp
@@ -7382,13 +7382,9 @@
   // NOTE: lambda classes are created with BeingDefined flag set up.
   // It means that ImportDefinition doesn't work for them and we should fill it
   // manually.
-  if (ToClass->isBeingDefined()) {
-    for (auto FromField : FromClass->fields()) {
-      auto ToFieldOrErr = import(FromField);
-      if (!ToFieldOrErr)
-        return ToFieldOrErr.takeError();
-    }
-  }
+  if (ToClass->isBeingDefined())
+    if (Error Err = ImportDeclContext(FromClass, /*ForceImport = */ true))
+      return std::move(Err);
 
   auto ToCallOpOrErr = import(E->getCallOperator());
   if (!ToCallOpOrErr)
Index: unittests/AST/ASTImporterTest.cpp
===================================================================
--- unittests/AST/ASTImporterTest.cpp
+++ unittests/AST/ASTImporterTest.cpp
@@ -2417,6 +2417,27 @@
   EXPECT_EQ(ToDFOutOfClass->getPreviousDecl(), ToDFInClass);
 }
 
+TEST_P(ImportFunctions, ImportImplicitFunctionsInLambda) {
+  Decl *FromTU = getTuDecl(
+      R"(
+      void foo() {
+        (void)[]() { ; };
+      }
+      )",
+      Lang_CXX11);
+  auto *FromD = FirstDeclMatcher<FunctionDecl>().match(
+      FromTU, functionDecl(hasName("foo")));
+  auto *ToD = Import(FromD, Lang_CXX);
+  EXPECT_TRUE(ToD);
+  Decl *ToTU = ToAST->getASTContext().getTranslationUnitDecl();
+  CXXRecordDecl *LambdaRec =
+      cast<LambdaExpr>(cast<CStyleCastExpr>(
+                           *cast<CompoundStmt>(ToD->getBody())->body_begin())
+                           ->getSubExpr())
+          ->getLambdaClass();
+  EXPECT_TRUE(LambdaRec->getDestructor());
+}
+
 struct ImportFriendFunctions : ImportFunctions {};
 
 TEST_P(ImportFriendFunctions, ImportFriendFunctionRedeclChainProto) {