diff --git a/src/gn/ninja_action_target_writer.cc b/src/gn/ninja_action_target_writer.cc
index 60d4204..c33fc6e 100644
--- a/src/gn/ninja_action_target_writer.cc
+++ b/src/gn/ninja_action_target_writer.cc
@@ -141,10 +141,16 @@
     out_ << std::endl;
   }
 
+  // The command line requires shell escaping to properly handle filenames
+  // with spaces.
+  PathOutput command_output(path_output_.current_dir(),
+                            settings_->build_settings()->root_path_utf8(),
+                            ESCAPE_NINJA_COMMAND);
+
   out_ << "  command = ";
-  path_output_.WriteFile(out_, settings_->build_settings()->python_path());
+  command_output.WriteFile(out_, settings_->build_settings()->python_path());
   out_ << " ";
-  path_output_.WriteFile(out_, target_->action_values().script());
+  command_output.WriteFile(out_, target_->action_values().script());
   for (const auto& arg : args.list()) {
     out_ << " ";
     SubstitutionWriter::WriteWithNinjaVariables(arg, args_escape_options, out_);
diff --git a/src/gn/ninja_action_target_writer_unittest.cc b/src/gn/ninja_action_target_writer_unittest.cc
index d57f149..8fcddb6 100644
--- a/src/gn/ninja_action_target_writer_unittest.cc
+++ b/src/gn/ninja_action_target_writer_unittest.cc
@@ -547,3 +547,46 @@
     EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
   }
 }
+
+// Check for proper escaping of actions with spaces in python & script.
+TEST(NinjaActionTargetWriter, ActionWithSpaces) {
+  Err err;
+  TestWithScope setup;
+
+  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  target.set_output_type(Target::ACTION);
+
+  target.action_values().set_script(SourceFile("//foo/my script.py"));
+  target.action_values().args() = SubstitutionList::MakeForTest("my argument");
+  target.config_values().inputs().push_back(SourceFile("//foo/input file.txt"));
+
+  target.action_values().outputs() =
+      SubstitutionList::MakeForTest("//out/Debug/foo.out");
+
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  setup.build_settings()->set_python_path(
+      base::FilePath(FILE_PATH_LITERAL("/Program Files/python")));
+
+  std::ostringstream out;
+  NinjaActionTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      R"(rule __foo_bar___rule)" "\n"
+// Escaping is different between Windows and Posix.
+#if defined(OS_WIN)
+      R"(  command = "/Program$ Files/python" "../../foo/my$ script.py" "my$ argument")" "\n"
+#else
+      R"(  command = /Program\$ Files/python ../../foo/my\$ script.py my\$ argument)" "\n"
+#endif
+      R"(  description = ACTION //foo:bar()
+  restat = 1
+
+build foo.out: __foo_bar___rule | ../../foo/my$ script.py ../../foo/input$ file.txt
+
+build obj/foo/bar.stamp: stamp foo.out
+)";
+  EXPECT_EQ(expected, out.str()) << expected << "--" << out.str();
+}
diff --git a/src/gn/path_output.cc b/src/gn/path_output.cc
index d2886d7..86c92e6 100644
--- a/src/gn/path_output.cc
+++ b/src/gn/path_output.cc
@@ -145,7 +145,7 @@
   } else {
     // Ninja (and none) escaping can avoid the intermediate string and
     // reprocessing of the inverse_current_dir_.
-    out << inverse_current_dir_;
+    EscapeStringToStream(out, inverse_current_dir_, options_);
     EscapeStringToStream(out, str, options_);
   }
 }