diff --git a/test-runner/android/test/ClassPathPackageInfoSource.java b/test-runner/android/test/ClassPathPackageInfoSource.java
index 12bc7f3..877075f 100644
--- a/test-runner/android/test/ClassPathPackageInfoSource.java
+++ b/test-runner/android/test/ClassPathPackageInfoSource.java
@@ -226,8 +226,11 @@
                 String className = apkClassNames.nextElement();
 
                 if (className.startsWith(packageName)) {
+                    String subPackageName = packageName;
                     int lastPackageSeparator = className.lastIndexOf('.');
-                    String subPackageName = className.substring(0, lastPackageSeparator);
+                    if (lastPackageSeparator > 0) {
+                        subPackageName = className.substring(0, lastPackageSeparator);
+                    }
                     if (subPackageName.length() > packageName.length()) {
                         subpackageNames.add(subPackageName);
                     } else if (isToplevelClass(className)) {
diff --git a/test-runner/android/test/InstrumentationTestRunner.java b/test-runner/android/test/InstrumentationTestRunner.java
index f038612..044f555 100644
--- a/test-runner/android/test/InstrumentationTestRunner.java
+++ b/test-runner/android/test/InstrumentationTestRunner.java
@@ -300,16 +300,17 @@
         }
 
         if (testClassesArg == null) {
-            TestSuite testSuite = null;
             if (mPackageOfTests != null) {
                 testSuiteBuilder.includePackages(mPackageOfTests);
             } else {
-                testSuite = getTestSuite();
-                testSuiteBuilder.addTestSuite(testSuite);
-            }
-
-            if (testSuite == null) {
-                testSuiteBuilder.includePackages(getTargetContext().getPackageName());
+                TestSuite testSuite = getTestSuite();
+                if (testSuite != null) {
+                    testSuiteBuilder.addTestSuite(testSuite);
+                } else {
+                    // no package or class bundle arguments were supplied, and no test suite 
+                    // provided so add all tests in application
+                    testSuiteBuilder.includePackages("");
+                }
             }
         } else {
             parseTestClasses(testClassesArg, testSuiteBuilder);