diff --git a/Android.mk b/Android.mk
index 8fd63ee4..b847425 100644
--- a/Android.mk
+++ b/Android.mk
@@ -1558,6 +1558,7 @@
 LOCAL_SOURCE_FILES_ALL_GENERATED := true
 LOCAL_SRC_FILES := \
     tools/streaming_proto/stream.proto \
+    cmds/am/proto/instrumentation_data.proto \
     $(call all-proto-files-under, core/proto) \
     $(call all-proto-files-under, libs/incident/proto)
 include $(BUILD_HOST_JAVA_LIBRARY)
diff --git a/cmds/am/src/com/android/commands/am/Instrument.java b/cmds/am/src/com/android/commands/am/Instrument.java
index 93b9f58..d79b1a6 100644
--- a/cmds/am/src/com/android/commands/am/Instrument.java
+++ b/cmds/am/src/com/android/commands/am/Instrument.java
@@ -47,6 +47,16 @@
 
 /**
  * Runs the am instrument command
+ *
+ * Test Result Code:
+ * 1 - Test running
+ * 0 - Test passed
+ * -2 - assertion failure
+ * -1 - other exceptions
+ *
+ * Session Result Code:
+ * -1: Success
+ * other: Failure
  */
 public class Instrument {
     public static final String DEFAULT_LOG_DIR = "instrument-logs";