diff --git a/packages/primevue/src/selectbutton/style/SelectButtonStyle.js b/packages/primevue/src/selectbutton/style/SelectButtonStyle.js
index 5ea5d598b..72533dc05 100644
--- a/packages/primevue/src/selectbutton/style/SelectButtonStyle.js
+++ b/packages/primevue/src/selectbutton/style/SelectButtonStyle.js
@@ -20,14 +20,14 @@ const theme = ({ dt }) => `
 }
 
 .p-selectbutton .p-togglebutton:first-child {
-    border-left-width: 1px;
-    border-top-left-radius: ${dt('selectbutton.border.radius')};
-    border-bottom-left-radius: ${dt('selectbutton.border.radius')};
+    border-inline-start-width: 1px;
+    border-start-start-radius: ${dt('selectbutton.border.radius')};
+    border-end-start-radius: ${dt('selectbutton.border.radius')};
 }
 
 .p-selectbutton .p-togglebutton:last-child {
-    border-top-right-radius: ${dt('selectbutton.border.radius')};
-    border-bottom-right-radius: ${dt('selectbutton.border.radius')};
+    border-start-end-radius: ${dt('selectbutton.border.radius')};
+    border-end-end-radius: ${dt('selectbutton.border.radius')};
 }
 
 .p-selectbutton.p-invalid {