diff --git a/sandboxed_api/tools/clang_generator/emitter_test.cc b/sandboxed_api/tools/clang_generator/emitter_test.cc
index 550765b..bf51662 100644
--- a/sandboxed_api/tools/clang_generator/emitter_test.cc
+++ b/sandboxed_api/tools/clang_generator/emitter_test.cc
@@ -52,7 +52,7 @@ TEST_F(EmitterTest, BasicFunctionality) {
 
   EmitterForTesting emitter;
   RunFrontendAction(R"(extern "C" void ExposedFunction() {})",
-                    absl::make_unique<GeneratorAction>(emitter, options));
+                    std::make_unique<GeneratorAction>(emitter, options));
 
   EXPECT_THAT(emitter.functions_, SizeIs(1));
 
@@ -80,7 +80,7 @@ TEST_F(EmitterTest, RelatedTypes) {
     typedef struct { int member; } MyStruct;
     extern "C" void Structize(MyStruct* s);
         )",
-      absl::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
+      std::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
 
   // Types from "std" should be skipped
   EXPECT_THAT(emitter.rendered_types_["std"], IsEmpty());
@@ -106,7 +106,7 @@ TEST_F(EmitterTest, NestedStruct) {
     };
     extern "C" void Structize(A* s);
         )",
-      absl::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
+      std::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
 
   EXPECT_THAT(UglifyAll(emitter.rendered_types_[""]),
               ElementsAre("struct A {"
@@ -125,7 +125,7 @@ TEST_F(EmitterTest, NestedAnonymousStruct) {
     };
     extern "C" void Structize(A* s);
         )",
-      absl::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
+      std::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
 
   EXPECT_THAT(UglifyAll(emitter.rendered_types_[""]),
               ElementsAre("struct A {"
@@ -144,7 +144,7 @@ TEST_F(EmitterTest, ParentNotCollected) {
     };
     extern "C" void Structize(A::B* s);
         )",
-      absl::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
+      std::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
 
   EXPECT_THAT(UglifyAll(emitter.rendered_types_[""]),
               ElementsAre("struct A {"
@@ -160,7 +160,7 @@ TEST_F(EmitterTest, RemoveQualifiers) {
     struct A { int data; };
     extern "C" void Structize(const A* in, A* out);
         )",
-      absl::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
+      std::make_unique<GeneratorAction>(emitter, GeneratorOptions()));
 
   EXPECT_THAT(UglifyAll(emitter.rendered_types_[""]),
               ElementsAre("struct A { int data; }"));
diff --git a/sandboxed_api/tools/clang_generator/generator.cc b/sandboxed_api/tools/clang_generator/generator.cc
index 0ffc157..20b3680 100644
--- a/sandboxed_api/tools/clang_generator/generator.cc
+++ b/sandboxed_api/tools/clang_generator/generator.cc
@@ -48,12 +48,25 @@ std::string GetOutputFilename(absl::string_view source_file) {
 }
 
 bool GeneratorASTVisitor::VisitFunctionDecl(clang::FunctionDecl* decl) {
-  if (!decl->isCXXClassMember() &&  // Skip classes
-      decl->isExternC() &&          // Skip non external functions
-      !decl->isTemplated() &&       // Skip function templates
-      // Process either all function or just the requested ones
-      (options_.function_names.empty() ||
-       options_.function_names.count(ToStringView(decl->getName())) > 0)) {
+  if (decl->isCXXClassMember() ||  // Skip classes
+      !decl->isExternC() ||        // Skip non external functions
+      decl->isTemplated()          // Skip function templates
+  ) {
+    return true;
+  }
+
+  // Process either all function or just the requested ones
+  if (bool all_functions = options_.function_names.empty();
+      all_functions ||
+      options_.function_names.count(ToStringView(decl->getName())) > 0) {
+    // Skip functions from system headers when all functions are requested.
+    // This allows to still specify standard library functions explicitly.
+    if (all_functions &&
+        decl->getASTContext().getSourceManager().isInSystemHeader(
+            decl->getBeginLoc())) {
+      return true;
+    }
+
     functions_.push_back(decl);
 
     collector_.CollectRelatedTypes(decl->getDeclaredReturnType());
diff --git a/sandboxed_api/tools/clang_generator/generator.h b/sandboxed_api/tools/clang_generator/generator.h
index 2b211b0..9881905 100644
--- a/sandboxed_api/tools/clang_generator/generator.h
+++ b/sandboxed_api/tools/clang_generator/generator.h
@@ -97,8 +97,8 @@ class GeneratorAction : public clang::ASTFrontendAction {
  private:
   std::unique_ptr<clang::ASTConsumer> CreateASTConsumer(
       clang::CompilerInstance&, llvm::StringRef in_file) override {
-    return absl::make_unique<GeneratorASTConsumer>(std::string(in_file),
-                                                   emitter_, options_);
+    return std::make_unique<GeneratorASTConsumer>(std::string(in_file),
+                                                  emitter_, options_);
   }
 
   bool hasCodeCompletionSupport() const override { return false; }
@@ -116,7 +116,7 @@ class GeneratorFactory : public clang::tooling::FrontendActionFactory {
  private:
 #if LLVM_VERSION_MAJOR >= 10
   std::unique_ptr<clang::FrontendAction> create() override {
-    return absl::make_unique<GeneratorAction>(emitter_, options_);
+    return std::make_unique<GeneratorAction>(emitter_, options_);
   }
 #else
   clang::FrontendAction* create() override {
diff --git a/sandboxed_api/tools/clang_generator/generator_tool.cc b/sandboxed_api/tools/clang_generator/generator_tool.cc
index f155198..578e103 100644
--- a/sandboxed_api/tools/clang_generator/generator_tool.cc
+++ b/sandboxed_api/tools/clang_generator/generator_tool.cc
@@ -136,7 +136,7 @@ absl::Status GeneratorMain(int argc, char* argv[]) {
   }
 
   if (int result = tool.run(
-          absl::make_unique<sapi::GeneratorFactory>(emitter, options).get());
+          std::make_unique<sapi::GeneratorFactory>(emitter, options).get());
       result != 0) {
     return absl::UnknownError("header generation failed");
   }