diff --git a/themes/chrome/main.css b/themes/chrome/main.css
index c93d837ce..9397e78e6 100644
--- a/themes/chrome/main.css
+++ b/themes/chrome/main.css
@@ -129,6 +129,7 @@ ToolButton[toolbar-look="true"]:pressed
 #tabbar
 {
     qproperty-tabPadding: -1;
+    qproperty-baseColor: 0;
 }
 
 #tabbar::scroller
diff --git a/themes/linux/main.css b/themes/linux/main.css
index b361e7023..36d56336e 100644
--- a/themes/linux/main.css
+++ b/themes/linux/main.css
@@ -70,6 +70,7 @@
 #tabbar
 {
     qproperty-tabPadding: -1;
+    qproperty-baseColor: 0;
 }
 
 #tabbar-button-right
diff --git a/themes/mac/main.css b/themes/mac/main.css
index a3048d57d..b2d975207 100644
--- a/themes/mac/main.css
+++ b/themes/mac/main.css
@@ -130,6 +130,7 @@ ToolButton[toolbar-look="true"]:pressed
 #tabbar
 {
     qproperty-tabPadding: -1;
+    qproperty-baseColor: 0;
 }
 
 #tabbar-button-right
diff --git a/themes/windows/main.css b/themes/windows/main.css
index 442153450..06d687cd3 100644
--- a/themes/windows/main.css
+++ b/themes/windows/main.css
@@ -135,6 +135,7 @@
     min-height: 30px;
     max-height: 30px;
     qproperty-tabPadding: 3;
+    qproperty-baseColor: transparent;
 }
 
 #tab-icon