diff --git a/index.bs b/index.bs
index 6f901f0c..5bf5ba67 100644
--- a/index.bs
+++ b/index.bs
@@ -1344,7 +1344,7 @@ Parsers encountering a reserved value of [=headphones_rendering_mode=] SHALL ign
 <dfn noexport>rendering_config_extension_bytes</dfn> represents reserved bytes for future use. Parsers that don't understand these bytes SHOULD ignore them.
 
 
-### Mix Gain Parameter Defintion Syntax and Semantics ### {#syntax-mixgain-parameter-definition}
+### Mix Gain Parameter Definition Syntax and Semantics ### {#syntax-mixgain-parameter-definition}
 
 The <dfn noexport>MixGainParamDefinition()</dfn> class provides the parameter definition for any mix gains that need to be applied to a signal.