diff --git a/.travis.yml b/.travis.yml
index 9a0e907..3363ccf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,20 @@
-dist: focal
 language: java
+os:
+  - linux
+  - osx
+dist: focal
+addons:
+  apt:
+    packages:
+      - cpio
+      - libblkid-dev
+      - liblz4-tool
+      - device-tree-compiler
+      - python3
+      - python-all
 before_install:
-  - sudo apt -qq update
-  - sudo apt install -y libblkid-dev liblz4-tool device-tree-compiler
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew update          ; fi
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew install lz4 dtc gradle; fi
 script:
   - ./gradlew check
   - ./gradlew clean
diff --git a/bbootimg/src/main/kotlin/avb/Avb.kt b/bbootimg/src/main/kotlin/avb/Avb.kt
index 32e3ff5..c1b92be 100644
--- a/bbootimg/src/main/kotlin/avb/Avb.kt
+++ b/bbootimg/src/main/kotlin/avb/Avb.kt
@@ -196,7 +196,7 @@ class Avb {
         }
 
         // aux - desc
-        var descriptors: List<Any> = mutableListOf()
+        var descriptors = listOf<Any>()
         if (vbMetaHeader.descriptors_size > 0) {
             FileInputStream(image_file).use { fis ->
                 fis.skip(descStartOffset)
diff --git a/bbootimg/src/test/kotlin/avb/FooterTest.kt b/bbootimg/src/test/kotlin/avb/FooterTest.kt
index d6909c1..f7157b0 100644
--- a/bbootimg/src/test/kotlin/avb/FooterTest.kt
+++ b/bbootimg/src/test/kotlin/avb/FooterTest.kt
@@ -17,11 +17,11 @@ class FooterTest {
             it.skip(footerBytes.size - 64L)
             val footer = Footer(it)
             println(footer.toString())
-            assertEquals(1U, footer.versionMajor)
-            assertEquals(0U, footer.versionMinor)
-            assertEquals(512U.toULong(), footer.vbMetaSize)
-            assertEquals(28983296U.toULong(), footer.vbMetaOffset)
-            assertEquals(28983296U.toULong(), footer.originalImageSize)
+            assertEquals(1, footer.versionMajor)
+            assertEquals(0, footer.versionMinor)
+            assertEquals(512, footer.vbMetaSize)
+            assertEquals(28983296, footer.vbMetaOffset)
+            assertEquals(28983296, footer.originalImageSize)
         }
     }
 
diff --git a/bbootimg/src/test/kotlin/cfig/io/Struct3Test.kt b/bbootimg/src/test/kotlin/cfig/io/Struct3Test.kt
index a790e1d..1a0fc76 100644
--- a/bbootimg/src/test/kotlin/cfig/io/Struct3Test.kt
+++ b/bbootimg/src/test/kotlin/cfig/io/Struct3Test.kt
@@ -103,9 +103,9 @@ class Struct3Test {
 
         //pack legal
         Assert.assertEquals("61",
-                Helper.toHexString(Struct3("!c").pack(Character('a'))))
+                Helper.toHexString(Struct3("!c").pack('a')))
         Assert.assertEquals("61",
-                Helper.toHexString(Struct3("c").pack(Character('a'))))
+                Helper.toHexString(Struct3("c").pack('a')))
         Assert.assertEquals("616263",
                 Helper.toHexString(Struct3("3c").pack('a', 'b', 'c')))
 
diff --git a/integrationTest.py b/integrationTest.py
index 1e579ea..b488cf9 100755
--- a/integrationTest.py
+++ b/integrationTest.py
@@ -62,8 +62,8 @@ def verifySingleJson(jsonFile):
             decompressXZ(it + ".xz", v)
         else:
             raise
-    subprocess.check_call("gradle unpack", shell = True)
-    subprocess.check_call("gradle pack", shell = True)
+    subprocess.check_call("./gradlew unpack", shell = True)
+    subprocess.check_call("./gradlew pack", shell = True)
     for k, v in verifyItems["hash"].items():
         log.info("%s : %s" % (k, v))
         unittest.TestCase().assertEqual(v, hashFile(k))
diff --git a/src/integrationTest/resources b/src/integrationTest/resources
index 7cd84fb..9aa5996 160000
--- a/src/integrationTest/resources
+++ b/src/integrationTest/resources
@@ -1 +1 @@
-Subproject commit 7cd84fb4f31151410d413d138e8ae1c35cd40dd9
+Subproject commit 9aa59964ee1d0c828c8655ba7916f162c7721703