diff --git a/src/front/wgsl/conv.rs b/src/front/wgsl/conv.rs
index ba41648757..6da7ee4ced 100644
--- a/src/front/wgsl/conv.rs
+++ b/src/front/wgsl/conv.rs
@@ -32,7 +32,6 @@ pub fn map_built_in(word: &str, span: Span) -> Result<crate::BuiltIn, Error<'_>>
         "local_invocation_id" => crate::BuiltIn::LocalInvocationId,
         "local_invocation_index" => crate::BuiltIn::LocalInvocationIndex,
         "workgroup_id" => crate::BuiltIn::WorkGroupId,
-        "workgroup_size" => crate::BuiltIn::WorkGroupSize,
         "num_workgroups" => crate::BuiltIn::NumWorkGroups,
         _ => return Err(Error::UnknownBuiltin(span)),
     })