diff --git a/yardang/shibuya.css b/yardang/shibuya.css
index 7b6fcb1a..b1662c60 100644
--- a/yardang/shibuya.css
+++ b/yardang/shibuya.css
@@ -8,7 +8,8 @@ a.reference > img {
     max-width: unset;
 }
 
-/* Shibuya ships its own copy button; hide the sphinx-copybutton duplicate */
-.copybtn {
+/* Shibuya ships its own copy button; hide the sphinx-copybutton duplicate.
+   Must match copybutton.css's `button.copybtn` specificity to win. */
+button.copybtn {
     display: none;
 }
diff --git a/yardang/sphinxawesome_theme.css b/yardang/sphinxawesome_theme.css
index e3659221..17ba81ba 100644
--- a/yardang/sphinxawesome_theme.css
+++ b/yardang/sphinxawesome_theme.css
@@ -27,8 +27,9 @@ a.reference > img {
     background-color: rgba(255, 255, 255, 0.08) !important;
 }
 
-/* Hide duplicate copybtn */
-.copybtn {
+/* Hide the sphinx-copybutton duplicate; the theme ships its own button.copy.
+   Must match copybutton.css's `button.copybtn` specificity to win. */
+button.copybtn {
     display: none;
 }