diff --git a/av1_codec_registration.src.html b/av1_codec_registration.src.html
index acf0870f..97e34e66 100644
--- a/av1_codec_registration.src.html
+++ b/av1_codec_registration.src.html
@@ -108,7 +108,7 @@
   <dt><dfn dict-member for=VideoEncoderEncodeOptionsForAv1>quantizer</dfn></dt>
   <dd>
     Sets per-frame quantizer value.
-    In [[AV1]] the quantizer threshold can be varied from 0 to 63
+    In [[AV1]] the quantizer index can be varied from 0 to 255
   </dd>
 </dl>
 
diff --git a/vp9_codec_registration.src.html b/vp9_codec_registration.src.html
index 93a0a503..a7ca9c73 100644
--- a/vp9_codec_registration.src.html
+++ b/vp9_codec_registration.src.html
@@ -106,7 +106,7 @@
   <dt><dfn dict-member for=VideoEncoderEncodeOptionsForVp9>quantizer</dfn></dt>
   <dd>
     Sets per-frame quantizer value.
-    In [[VP9]] the quantizer threshold can be varied from 0 to 63
+    In [[VP9]] the quantizer index can be varied from 0 to 255
   </dd>
 </dl>