diff --git a/src/gn/ninja_copy_target_writer_unittest.cc b/src/gn/ninja_copy_target_writer_unittest.cc
index 1b5077a..e094f80 100644
--- a/src/gn/ninja_copy_target_writer_unittest.cc
+++ b/src/gn/ninja_copy_target_writer_unittest.cc
@@ -6,6 +6,7 @@
 #include <sstream>
 
 #include "gn/ninja_copy_target_writer.h"
+#include "gn/substitution_list.h"
 #include "gn/target.h"
 #include "gn/test_with_scope.h"
 #include "util/test/test.h"
@@ -124,3 +125,101 @@
   std::string out_str = out.str();
   EXPECT_EQ(expected_linux, out_str);
 }
+
+TEST(NinjaCopyTargetWriter, NoSourcesInOutputs) {
+  Err err;
+  TestWithScope setup;
+  setup.build_settings()->set_no_stamp_files(true);
+
+  // First with a single action / output / copy
+  {
+    Target action1(setup.settings(), Label(SourceDir("//foo/"), "action1"));
+    action1.set_output_type(Target::ACTION);
+    action1.visibility().SetPublic();
+    action1.SetToolchain(setup.toolchain());
+    action1.action_values().outputs() =
+        SubstitutionList::MakeForTest("//out/Debug/action1.out");
+    ASSERT_TRUE(action1.OnResolved(&err));
+
+    Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+    target.set_output_type(Target::COPY_FILES);
+    target.sources().push_back(
+        action1.computed_outputs()[0].AsSourceFile(setup.build_settings()));
+    target.SetToolchain(setup.toolchain());
+    target.private_deps().push_back(LabelTargetPair(&action1));
+    target.action_values().outputs() =
+        SubstitutionList::MakeForTest("//out/Debug/{{source_name_part}}.copy");
+    ASSERT_TRUE(target.OnResolved(&err));
+
+    std::ostringstream out;
+    std::vector<OutputFile> ninja_outputs;
+    NinjaCopyTargetWriter writer(&target, out);
+    writer.SetNinjaOutputs(&ninja_outputs);
+    writer.Run();
+
+    const char expected_linux[] =
+        "build action1.copy: copy action1.out || phony/foo/action1\n"
+        "\n"
+        "build phony/foo/bar: phony action1.copy\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected_linux, out_str);
+
+    EXPECT_EQ(2u, ninja_outputs.size());
+    EXPECT_EQ(ninja_outputs[0].value(), "action1.copy");
+    EXPECT_EQ(ninja_outputs[1].value(), "phony/foo/bar");
+  }
+
+  // Second, with two actions / outputs / copies, which is what trigerred
+  // the bug in https://gn.issues.chromium.org/448860851
+  {
+    Target action1(setup.settings(), Label(SourceDir("//foo/"), "action1"));
+    action1.set_output_type(Target::ACTION);
+    action1.visibility().SetPublic();
+    action1.SetToolchain(setup.toolchain());
+    action1.action_values().outputs() =
+        SubstitutionList::MakeForTest("//out/Debug/action1.out");
+    ASSERT_TRUE(action1.OnResolved(&err));
+
+    Target action2(setup.settings(), Label(SourceDir("//foo/"), "action2"));
+    action2.set_output_type(Target::ACTION);
+    action2.visibility().SetPublic();
+    action2.SetToolchain(setup.toolchain());
+    action2.action_values().outputs() =
+        SubstitutionList::MakeForTest("//out/Debug/action2.out");
+    ASSERT_TRUE(action2.OnResolved(&err));
+
+    Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+    target.set_output_type(Target::COPY_FILES);
+    target.sources().push_back(
+        action1.computed_outputs()[0].AsSourceFile(setup.build_settings()));
+    target.sources().push_back(
+        action2.computed_outputs()[0].AsSourceFile(setup.build_settings()));
+    target.SetToolchain(setup.toolchain());
+    target.private_deps().push_back(LabelTargetPair(&action1));
+    target.private_deps().push_back(LabelTargetPair(&action2));
+    target.action_values().outputs() =
+        SubstitutionList::MakeForTest("//out/Debug/{{source_name_part}}.copy");
+    ASSERT_TRUE(target.OnResolved(&err));
+
+    std::ostringstream out;
+    std::vector<OutputFile> ninja_outputs;
+    NinjaCopyTargetWriter writer(&target, out);
+    writer.SetNinjaOutputs(&ninja_outputs);
+    writer.Run();
+
+    const char expected_linux[] =
+        "build phony/foo/bar.inputdeps: phony phony/foo/action1 "
+        "phony/foo/action2\n"
+        "build action1.copy: copy action1.out || phony/foo/bar.inputdeps\n"
+        "build action2.copy: copy action2.out || phony/foo/bar.inputdeps\n"
+        "\n"
+        "build phony/foo/bar: phony action1.copy action2.copy\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected_linux, out_str);
+
+    EXPECT_EQ(3u, ninja_outputs.size());
+    EXPECT_EQ(ninja_outputs[0].value(), "action1.copy");
+    EXPECT_EQ(ninja_outputs[1].value(), "action2.copy");
+    EXPECT_EQ(ninja_outputs[2].value(), "phony/foo/bar");
+  }
+}
diff --git a/src/gn/ninja_target_writer.cc b/src/gn/ninja_target_writer.cc
index 1bbe31e..e5248a1 100644
--- a/src/gn/ninja_target_writer.cc
+++ b/src/gn/ninja_target_writer.cc
@@ -571,10 +571,12 @@
            GeneralTool::kGeneralToolStamp;
   }
 
+  // These are not real outputs, so do not use WriteOutput() here.
+  // See https://gn.issues.chromium.org/448860851.
   out_ << "build ";
-  WriteOutput(input_stamp_or_phony);
+  path_output_.WriteFile(out_, input_stamp_or_phony);
   out_ << ": " << tool;
-  WriteOutputs(outs);
+  path_output_.WriteFiles(out_, outs);
   out_ << "\n";
   return std::vector<OutputFile>{input_stamp_or_phony};
 }