diff --git a/UI/data/themes/Dark.qss b/UI/data/themes/Dark.qss
index 3f201fd05..ab46aabf1 100644
--- a/UI/data/themes/Dark.qss
+++ b/UI/data/themes/Dark.qss
@@ -121,6 +121,13 @@ SourceTree QLineEdit {
     border-radius: none;
 }
 
+/* macOS Separator Fix */
+QMainWindow::separator {
+    background: transparent;
+    width: 4px;
+    height: 4px;
+}
+
 /* Dock Widget */
 
 QDockWidget {
diff --git a/UI/data/themes/System.qss b/UI/data/themes/System.qss
index ac84d40dd..c7cae9980 100644
--- a/UI/data/themes/System.qss
+++ b/UI/data/themes/System.qss
@@ -138,6 +138,13 @@ QLabel#errorLabel {
     font-weight: bold;
 }
 
+/* macOS Separator Fix */
+QMainWindow::separator {
+    background: transparent;
+    width: 4px;
+    height: 4px;
+}
+
 /* About dialog */
 
 * [themeID="aboutName"] {