diff --git a/devtools/client/shared/components/tabs/tabs.css b/devtools/client/shared/components/tabs/tabs.css
index 0e70549c55..12901c4026 100644
--- a/devtools/client/shared/components/tabs/tabs.css
+++ b/devtools/client/shared/components/tabs/tabs.css
@@ -46,7 +46,7 @@
 .tabs .all-tabs-menu  {
   position: absolute;
   top: 0;
-  offset-inline-end: 0;
+  inset-inline-end: 0;
   width: 15px;
   height: 100%;
   border-inline-start: 1px solid var(--theme-splitter-color);
diff --git a/devtools/client/themes/common.css b/devtools/client/themes/common.css
index 133770150c..8b807d0dba 100644
--- a/devtools/client/themes/common.css
+++ b/devtools/client/themes/common.css
@@ -652,7 +652,7 @@ checkbox:-moz-focusring {
 .devtools-searchinput-clear {
   position: absolute;
   top: 3.5px;
-  offset-inline-end: 7px;
+  inset-inline-end: 7px;
   padding: 0;
   border: 0;
   width: 16px;
diff --git a/devtools/client/themes/widgets.css b/devtools/client/themes/widgets.css
index a8c1dc7349..3e5fa457ee 100644
--- a/devtools/client/themes/widgets.css
+++ b/devtools/client/themes/widgets.css
@@ -216,7 +216,7 @@
   content: "";
   position: absolute;
   top: 1px;
-  offset-inline-start: 0;
+  inset-inline-start: 0;
   width: 12px;
   height: 22px;
   background-repeat: no-repeat;
diff --git a/devtools/server/actors/highlighters.css b/devtools/server/actors/highlighters.css
index 87375ea36a..3cc9265851 100644
--- a/devtools/server/actors/highlighters.css
+++ b/devtools/server/actors/highlighters.css
@@ -521,8 +521,8 @@
   width: 16px;
   height: 16px;
   position: absolute;
-  offset-inline-start: 3px;
-  offset-block-start: 3px;
+  inset-inline-start: 3px;
+  inset-block-start: 3px;
   box-shadow: 0px 0px 0px black;
   border: solid 1px #fff;
 }
diff --git a/layout/style/res/html.css b/layout/style/res/html.css
index 8593abaab7..0ce8901252 100644
--- a/layout/style/res/html.css
+++ b/layout/style/res/html.css
@@ -809,8 +809,8 @@ input[type="date"] > xul|datetimebox {
 
 dialog {
   position: absolute;
-  offset-inline-start: 0;
-  offset-inline-end: 0;
+  inset-inline-start: 0;
+  inset-inline-end: 0;
   color: black;
   margin: auto;
   border-width: initial;