diff --git a/tools/zipalign/Android.bp b/tools/zipalign/Android.bp
index 8cab04c..0e1d58e 100644
--- a/tools/zipalign/Android.bp
+++ b/tools/zipalign/Android.bp
@@ -70,6 +70,7 @@
         "libgmock",
     ],
     data: [
+         "tests/data/archiveWithOneDirectoryEntry.zip",
          "tests/data/diffOrders.zip",
          "tests/data/holes.zip",
          "tests/data/unaligned.zip",
diff --git a/tools/zipalign/ZipAlign.cpp b/tools/zipalign/ZipAlign.cpp
index 08f67ff..23840e3 100644
--- a/tools/zipalign/ZipAlign.cpp
+++ b/tools/zipalign/ZipAlign.cpp
@@ -22,6 +22,19 @@
 
 namespace android {
 
+// An entry is considered a directory if it has a stored size of zero
+// and it ends with '/' or '\' character.
+static bool isDirectory(ZipEntry* entry) {
+   if (entry->getUncompressedLen() != 0) {
+       return false;
+   }
+
+   const char* name = entry->getFileName();
+   size_t nameLength = strlen(name);
+   char lastChar = name[nameLength-1];
+   return lastChar == '/' || lastChar == '\\';
+}
+
 static int getAlignment(bool pageAlignSharedLibs, int defaultAlignment,
     ZipEntry* pEntry) {
 
@@ -59,7 +72,7 @@
             return 1;
         }
 
-        if (pEntry->isCompressed()) {
+        if (pEntry->isCompressed() || isDirectory(pEntry)) {
             /* copy the entry without padding */
             //printf("--- %s: orig at %ld len=%ld (compressed)\n",
             //    pEntry->getFileName(), (long) pEntry->getFileOffset(),
@@ -160,7 +173,13 @@
                 printf("%8jd %s (OK - compressed)\n",
                     (intmax_t) pEntry->getFileOffset(), pEntry->getFileName());
             }
-        } else {
+        } else if(isDirectory(pEntry)) {
+            // Directory entries do not need to be aligned.
+            if (verbose)
+                printf("%8jd %s (OK - directory)\n",
+                       (intmax_t) pEntry->getFileOffset(), pEntry->getFileName());
+            continue;
+       } else {
             off_t offset = pEntry->getFileOffset();
             const int alignTo = getAlignment(pageAlignSharedLibs, alignment, pEntry);
             if ((offset % alignTo) != 0) {
diff --git a/tools/zipalign/tests/data/archiveWithOneDirectoryEntry.zip b/tools/zipalign/tests/data/archiveWithOneDirectoryEntry.zip
new file mode 100644
index 0000000..00be0ce
--- /dev/null
+++ b/tools/zipalign/tests/data/archiveWithOneDirectoryEntry.zip
Binary files differ
diff --git a/tools/zipalign/tests/src/align_test.cpp b/tools/zipalign/tests/src/align_test.cpp
index ff45187..a8433fa 100644
--- a/tools/zipalign/tests/src/align_test.cpp
+++ b/tools/zipalign/tests/src/align_test.cpp
@@ -12,6 +12,28 @@
 using namespace android;
 using namespace base;
 
+// This load the whole file to memory so be careful!
+static bool sameContent(const std::string& path1, const std::string& path2) {
+  std::string f1;
+  if (!ReadFileToString(path1, &f1)) {
+    printf("Unable to read '%s' content: %m\n", path1.c_str());
+    return false;
+  }
+
+  std::string f2;
+  if (!ReadFileToString(path2, &f2)) {
+    printf("Unable to read '%s' content %m\n", path1.c_str());
+    return false;
+  }
+
+  if (f1.size() != f2.size()) {
+    printf("File '%s' and '%s' are not the same\n", path1.c_str(), path2.c_str());
+    return false;
+  }
+
+  return f1.compare(f2) == 0;
+}
+
 static std::string GetTestPath(const std::string& filename) {
   static std::string test_data_dir = android::base::GetExecutableDirectory() + "/tests/data/";
   return test_data_dir + filename;
@@ -87,3 +109,21 @@
   int verified = verify(dst.c_str(), 4, false, true);
   ASSERT_EQ(0, verified);
 }
+
+TEST(Align, DirectoryEntryDoNotRequireAlignment) {
+  const std::string src = GetTestPath("archiveWithOneDirectoryEntry.zip");
+  int verified = verify(src.c_str(), 4, false, true);
+  ASSERT_EQ(0, verified);
+}
+
+TEST(Align, DirectoryEntry) {
+  const std::string src = GetTestPath("archiveWithOneDirectoryEntry.zip");
+  const std::string dst = GetTempPath("archiveWithOneDirectoryEntry_out.zip");
+
+  int processed = process(src.c_str(), dst.c_str(), 4, true, false, 4096);
+  ASSERT_EQ(0, processed);
+  ASSERT_EQ(true, sameContent(src, dst));
+
+  int verified = verify(dst.c_str(), 4, false, true);
+  ASSERT_EQ(0, verified);
+}