diff --git a/src/quote.rs b/src/quote.rs
index 89b241d..6ed637e 100644
--- a/src/quote.rs
+++ b/src/quote.rs
@@ -188,7 +188,7 @@ impl IoctlClient {
         if self.supplemental_size.is_none() {
             let size = unsafe { dcap_get_supplemental_data_size(self.handle()?) };
             trace!("DCAP supplemental data size is {}", size);
-            self.quote_size = Some(size);
+            self.supplemental_size = Some(size);
         }
 
         Ok(*self.supplemental_size.as_ref().unwrap())