diff --git a/tools/bit/adb.cpp b/tools/bit/adb.cpp
index 0c8424d..c8faf5c 100644
--- a/tools/bit/adb.cpp
+++ b/tools/bit/adb.cpp
@@ -283,10 +283,19 @@
     cmd.AddArg("instrument");
     cmd.AddArg("-w");
     cmd.AddArg("-m");
-    if (className.length() > 0) {
-        cmd.AddArg("-e");
-        cmd.AddArg("class");
-        cmd.AddArg(className);
+    const int classLen = className.length();
+    if (classLen > 0) {
+        if (classLen > 1 && className[classLen - 1] == '.') {
+            cmd.AddArg("-e");
+            cmd.AddArg("package");
+
+            // "am" actually accepts without removing the last ".", but for cleanlines...
+            cmd.AddArg(className.substr(0, classLen - 1));
+        } else {
+            cmd.AddArg("-e");
+            cmd.AddArg("class");
+            cmd.AddArg(className);
+        }
     }
     cmd.AddArg(packageName + "/" + runner);
 
diff --git a/tools/bit/main.cpp b/tools/bit/main.cpp
index 5fb84c8..a7fbc2e 100644
--- a/tools/bit/main.cpp
+++ b/tools/bit/main.cpp
@@ -342,6 +342,10 @@
     fprintf(out, "      Builds and installs CtsProtoTestCases.apk, and runs the testWrite\n");
     fprintf(out, "      and testRepeated test methods on that class.\n");
     fprintf(out, "\n");
+    fprintf(out, "    bit CtsProtoTestCases:android.util.proto.cts.\n");
+    fprintf(out, "      Builds and installs CtsProtoTestCases.apk, and runs the tests in the java package\n");
+    fprintf(out, "      \"android.util.proto.cts\".\n");
+    fprintf(out, "\n");
     fprintf(out, "  Launching an Activity\n");
     fprintf(out, "  ---------------------\n");
     fprintf(out, "  To launch an activity, specify the activity class name after\n");