diff --git a/extensions/theme-2026/themes/2026-dark.json b/extensions/theme-2026/themes/2026-dark.json
index 8eb011c2443..d204a5506b0 100644
--- a/extensions/theme-2026/themes/2026-dark.json
+++ b/extensions/theme-2026/themes/2026-dark.json
@@ -199,8 +199,8 @@
 		"tab.unfocusedInactiveBackground": "#191A1B",
 		"tab.unfocusedInactiveForeground": "#444444",
 		"editorGroupHeader.tabsBackground": "#191A1B",
-		"tab.activeBorder": "#00000000",
-		"editorGroupHeader.tabsBorder": "#00000000",
+		"tab.activeBorder": "#121314",
+		"editorGroupHeader.tabsBorder": "#2A2B2CFF",
 		"breadcrumb.foreground": "#8C8C8C",
 		"breadcrumb.background": "#121314",
 		"breadcrumb.focusForeground": "#bfbfbf",
diff --git a/extensions/theme-2026/themes/2026-light.json b/extensions/theme-2026/themes/2026-light.json
index f963724d6b5..6df7171b0d2 100644
--- a/extensions/theme-2026/themes/2026-light.json
+++ b/extensions/theme-2026/themes/2026-light.json
@@ -203,8 +203,8 @@
 		"tab.unfocusedInactiveBackground": "#FAFAFD",
 		"tab.unfocusedInactiveForeground": "#BBBBBB",
 		"editorGroupHeader.tabsBackground": "#FAFAFD",
-		"tab.activeBorder": "#00000000",
-		"editorGroupHeader.tabsBorder": "#00000000",
+		"tab.activeBorder": "#FFFFFF",
+		"editorGroupHeader.tabsBorder": "#F0F1F2FF",
 		"breadcrumb.foreground": "#606060",
 		"breadcrumb.background": "#FFFFFF",
 		"breadcrumb.focusForeground": "#202020",