diff --git a/index.src.html b/index.src.html
index 0a6ea365..34c07623 100644
--- a/index.src.html
+++ b/index.src.html
@@ -2176,7 +2176,7 @@
   <dt><dfn dict-member for=VideoEncoderConfig>bitrate</dfn></dt>
   <dd>
     The average bitrate of the encoded video given in units of bits per second.
-      
+
     NOTE: Authors are encouraged to additionally provide a
     {{VideoEncoderConfig/framerate}} to inform rate control.
   </dd>
@@ -3871,7 +3871,7 @@
             subsample for |plane|.
         4. If |rect|.{{DOMRectReadOnly/x}} is not a multiple of |sampleWidth|,
             return `false`.
-        5. If |rect|.{{DOMRectReadOnly/y}} is not a multiple of |sampleHeight|, 
+        5. If |rect|.{{DOMRectReadOnly/y}} is not a multiple of |sampleHeight|,
             return `false`.
         8. Increment |planeIndex| by `1`.
     5. Return `true`.
@@ -4405,10 +4405,10 @@
 };
 
 dictionary VideoColorSpaceInit {
-  VideoColorPrimaries primaries;
-  VideoTransferCharacteristics transfer;
-  VideoMatrixCoefficients matrix;
-  boolean fullRange;
+  VideoColorPrimaries? primaries;
+  VideoTransferCharacteristics? transfer;
+  VideoMatrixCoefficients? matrix;
+  boolean? fullRange;
 };
 </xmp>