diff --git a/include/oboe/AudioStream.h b/include/oboe/AudioStream.h
index 0d8fc76e0..c4b22fee9 100644
--- a/include/oboe/AudioStream.h
+++ b/include/oboe/AudioStream.h
@@ -268,6 +268,7 @@ class AudioStream : public AudioStreamBase {
 
     /**
      * Get the estimated time that the frame at `framePosition` entered or left the audio processing
+     * pipeline.
      *
      * This can be used to coordinate events and interactions with the external environment, and to
      * estimate the latency of an audio stream. An example of usage can be found in the hello-oboe
@@ -288,6 +289,7 @@ class AudioStream : public AudioStreamBase {
 
     /**
      * Get the estimated time that the frame at `framePosition` entered or left the audio processing
+     * pipeline.
      *
      * This can be used to coordinate events and interactions with the external environment, and to
      * estimate the latency of an audio stream. An example of usage can be found in the hello-oboe
diff --git a/include/oboe/Definitions.h b/include/oboe/Definitions.h
index c2eabfff8..0111a94a9 100644
--- a/include/oboe/Definitions.h
+++ b/include/oboe/Definitions.h
@@ -473,8 +473,8 @@ namespace oboe {
      * The time at which the frame at `position` was presented
      */
     struct FrameTimestamp {
-        int64_t position;
-        int64_t timestamp;
+        int64_t position; // in frames
+        int64_t timestamp; // in nanoseconds
     };