diff --git a/themes/classic/global/mac/outliner.css b/themes/classic/global/mac/outliner.css
index b5cfd7bf273..d5cc3b6d05f 100644
--- a/themes/classic/global/mac/outliner.css
+++ b/themes/classic/global/mac/outliner.css
@@ -71,8 +71,9 @@ outlinerchildren:-moz-outliner-cell-text(selected, focus) {
   color: HighlightText;
 }
 
-outlinerbody:-moz-outliner-cell-text(primary) {
-  border: 2px solid transparent;
+outlinerchildren:-moz-outliner-cell-text(primary) {
+  border-top: 1px solid transparent;
+  border-bottom: 1px solid transparent;
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, drop) {
@@ -81,19 +82,19 @@ outlinerchildren:-moz-outliner-cell-text(primary, drop) {
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, dropBefore) {
-  border-top: 2px solid Highlight;
+  border-top: 1px solid Highlight;
 }
 
 outlinerchildren:-moz-outliner-cell-text(selected, primary, dropBefore) {
-  border-top: 2px solid HighlightText;
+  border-top: 1px solid HighlightText;
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, dropAfter) {
-  border-bottom: 2px solid Highlight;
+  border-bottom: 1px solid Highlight;
 }
 
 outlinerchildren:-moz-outliner-cell-text(selected, primary, dropAfter) {
-  border-bottom: 2px solid HighlightText;
+  border-bottom: 1px solid HighlightText;
 }
 
 
diff --git a/themes/classic/global/win/outliner.css b/themes/classic/global/win/outliner.css
index abcd6fa3450..a5057622c1f 100644
--- a/themes/classic/global/win/outliner.css
+++ b/themes/classic/global/win/outliner.css
@@ -77,8 +77,9 @@ outlinerchildren:-moz-outliner-cell-text(selected, focus) {
   color: HighlightText;
 }
 
-outlinerbody:-moz-outliner-cell-text(primary) {
-  border: 2px solid transparent;
+outlinerchildren:-moz-outliner-cell-text(primary) {
+  border-top: 1px solid transparent;
+  border-bottom: 1px solid transparent;
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, drop) {
@@ -87,19 +88,19 @@ outlinerchildren:-moz-outliner-cell-text(primary, drop) {
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, dropBefore) {
-  border-top: 2px solid Highlight;
+  border-top: 1px solid Highlight;
 }
 
 outlinerchildren:-moz-outliner-cell-text(selected, primary, dropBefore) {
-  border-top: 2px solid HighlightText;
+  border-top: 1px solid HighlightText;
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, dropAfter) {
-  border-bottom: 2px solid Highlight;
+  border-bottom: 1px solid Highlight;
 }
 
 outlinerchildren:-moz-outliner-cell-text(selected, primary, dropAfter) {
-  border-bottom: 2px solid HighlightText;
+  border-bottom: 1px solid HighlightText;
 }
 
 
diff --git a/themes/modern/global/outliner.css b/themes/modern/global/outliner.css
index d8e4f19aa94..0d790903ccd 100644
--- a/themes/modern/global/outliner.css
+++ b/themes/modern/global/outliner.css
@@ -96,8 +96,9 @@ outlinerchildren:-moz-outliner-cell-text(selected, focus) {
   color: #FFFFFF;
 }
 
-outlinerbody:-moz-outliner-cell-text(primary) {
-  border: 2px solid transparent;
+outlinerchildren:-moz-outliner-cell-text(primary) {
+  border-top: 1px solid transparent;
+  border-bottom: 1px solid transparent;
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, drop) {
@@ -106,19 +107,19 @@ outlinerchildren:-moz-outliner-cell-text(primary, drop) {
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, dropBefore) {
-  border-top: 2px solid #424F63;
+  border-top: 1px solid #424F63;
 }
 
 outlinerchildren:-moz-outliner-cell-text(selected, primary, dropBefore) {
-  border-top: 2px solid #FFFFFF;
+  border-top: 1px solid #FFFFFF;
 }
 
 outlinerchildren:-moz-outliner-cell-text(primary, dropAfter) {
-  border-bottom: 2px solid #424F63;
+  border-bottom: 1px solid #424F63;
 }
 
 outlinerchildren:-moz-outliner-cell-text(selected, primary, dropAfter) {
-  border-bottom: 2px solid #FFFFFF;
+  border-bottom: 1px solid #FFFFFF;
 }