diff --git a/include/libyuv/planar_functions.h b/include/libyuv/planar_functions.h
index f93447214..678074a14 100644
--- a/include/libyuv/planar_functions.h
+++ b/include/libyuv/planar_functions.h
@@ -766,6 +766,10 @@ int ARGBPolynomial(const uint8_t* src_argb,
 
 // Convert plane of 16 bit shorts to half floats.
 // Source values are multiplied by scale before storing as half float.
+//
+// Note: Unlike other libyuv functions that operate on uint16_t buffers, the
+// src_stride_y and dst_stride_y parameters of HalfFloatPlane() are in bytes,
+// not in units of uint16_t.
 LIBYUV_API
 int HalfFloatPlane(const uint16_t* src_y,
                    int src_stride_y,