diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index 23c93c7c..770636da 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -2821,8 +2821,8 @@
         margin-inline-start 0.2s var(--animation-easing-function), min-width 0.1s ease-out, max-width 0.1s ease-out !important;
     }
     #tabbrowser-tabs:not([movingtab]) .tabbrowser-tab[pinned] {
-      transition: -moz-box-flex 0.2s var(--animation-easing-function),
-        margin-inline-start 0.2s var(--animation-easing-function) !important;
+      transition: margin-inline-start 0.2s var(--animation-easing-function), min-width 0.1s ease-out,
+        max-width 0.1s ease-out !important;
     }
     #tabbrowser-tabs:not([movingtab]) .tab-content::before,
     #tabbrowser-tabs:not([movingtab]) .tab-content::after {
diff --git a/src/decoration/_animate.scss b/src/decoration/_animate.scss
index 6f795036..8290d949 100644
--- a/src/decoration/_animate.scss
+++ b/src/decoration/_animate.scss
@@ -40,9 +40,7 @@
         margin-inline-start 0.2s var(--animation-easing-function), min-width 0.1s ease-out, max-width 0.1s ease-out !important;
     }
     &[pinned] {
-      transition: -moz-box-flex 0.2s var(--animation-easing-function),
-        margin-inline-start 0.2s var(--animation-easing-function) !important;
-
+      transition: margin-inline-start 0.2s var(--animation-easing-function), min-width 0.1s ease-out, max-width 0.1s ease-out !important;
     }
   }