diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index 93c1b61..02e4beae 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -251,10 +251,13 @@
     return false;
   }
 
-  for (StringPiece line : util::Tokenize(contents, ' ')) {
+  for (StringPiece line : util::Tokenize(contents, '\n')) {
     line = util::TrimWhitespace(line);
-    if (!line.empty()) {
-      out_arglist->emplace_back(line);
+    for (StringPiece arg : util::Tokenize(line, ' ')) {
+      arg = util::TrimWhitespace(arg);
+      if (!arg.empty()) {
+        out_arglist->emplace_back(arg);
+      }
     }
   }
   return true;
@@ -270,10 +273,13 @@
     return false;
   }
 
-  for (StringPiece line : util::Tokenize(contents, ' ')) {
+  for (StringPiece line : util::Tokenize(contents, '\n')) {
     line = util::TrimWhitespace(line);
-    if (!line.empty()) {
-      out_argset->emplace(line);
+    for (StringPiece arg : util::Tokenize(line, ' ')) {
+      arg = util::TrimWhitespace(arg);
+      if (!arg.empty()) {
+        out_argset->emplace(arg);
+      }
     }
   }
   return true;
diff --git a/tools/aapt2/util/Files_test.cpp b/tools/aapt2/util/Files_test.cpp
index 6c38080..618a3e0 100644
--- a/tools/aapt2/util/Files_test.cpp
+++ b/tools/aapt2/util/Files_test.cpp
@@ -25,6 +25,9 @@
 
 using ::android::base::StringPrintf;
 
+using ::testing::ElementsAre;
+using ::testing::UnorderedElementsAre;
+
 namespace aapt {
 namespace file {
 
@@ -34,9 +37,11 @@
 constexpr const char sTestDirSep = '/';
 #endif
 
-class FilesTest : public ::testing::Test {
+class FilesTest : public TestDirectoryFixture {
  public:
   void SetUp() override {
+    TestDirectoryFixture::SetUp();
+
     std::stringstream builder;
     builder << "hello" << sDirSep << "there";
     expected_path_ = builder.str();
@@ -66,6 +71,42 @@
   EXPECT_EQ(expected_path_, base);
 }
 
+TEST_F(FilesTest, AppendArgsFromFile) {
+  const std::string args_file = GetTestPath("args.txt");
+  WriteFile(args_file,
+            "  \n"
+            "arg1 arg2   arg3  \n"
+            "   arg4 arg5");
+  std::vector<std::string> args;
+  std::string error;
+  ASSERT_TRUE(AppendArgsFromFile(args_file, &args, &error));
+  EXPECT_THAT(args, ElementsAre("arg1", "arg2", "arg3", "arg4", "arg5"));
+}
+
+TEST_F(FilesTest, AppendArgsFromFile_InvalidFile) {
+  std::vector<std::string> args;
+  std::string error;
+  ASSERT_FALSE(AppendArgsFromFile(GetTestPath("not_found.txt"), &args, &error));
+}
+
+TEST_F(FilesTest, AppendSetArgsFromFile) {
+  const std::string args_file = GetTestPath("args.txt");
+  WriteFile(args_file,
+            "  \n"
+            "arg2 arg4   arg1  \n"
+            "   arg5 arg3");
+  std::unordered_set<std::string> args;
+  std::string error;
+  ASSERT_TRUE(AppendSetArgsFromFile(args_file, &args, &error));
+  EXPECT_THAT(args, UnorderedElementsAre("arg1", "arg2", "arg3", "arg4", "arg5"));
+}
+
+TEST_F(FilesTest, AppendSetArgsFromFile_InvalidFile) {
+  std::unordered_set<std::string> args;
+  std::string error;
+  ASSERT_FALSE(AppendSetArgsFromFile(GetTestPath("not_found.txt"), &args, &error));
+}
+
 #ifdef _WIN32
 TEST_F(FilesTest, WindowsMkdirsLongPath) {
   // Creating directory paths longer than the Windows maximum path length (260 charatcers) should