diff --git a/docs/labwc-theme.5.scd b/docs/labwc-theme.5.scd
index fff52721..5b267f35 100644
--- a/docs/labwc-theme.5.scd
+++ b/docs/labwc-theme.5.scd
@@ -281,6 +281,9 @@ all are supported.
 	Height of boxes in workspace switcher in pixels. Setting to 0 disables
 	boxes. Default is 20.
 
+*osd.workspace-switcher.boxes.border.width*
+	Border width of boxes in workspace switcher in pixels. Default is 2.
+
 *snapping.overlay.region.bg.enabled* [yes|no]
 	Show a filled rectangle as an overlay when a window is snapped to a
 	region. Default is yes for hardware-based renderers and no for
diff --git a/docs/themerc b/docs/themerc
index 6417d5bd..7ac293f7 100644
--- a/docs/themerc
+++ b/docs/themerc
@@ -96,6 +96,7 @@ osd.window-switcher.preview.border.color: #dddda6,#000000,#dddda6
 
 osd.workspace-switcher.boxes.width: 20
 osd.workspace-switcher.boxes.height: 20
+osd.workspace-switcher.boxes.border.width: 2
 
 # Default values for following options change depending on the rendering
 # backend. For software-based renderers, *.bg.enabled is "no" and
diff --git a/include/theme.h b/include/theme.h
index cbdee135..283538d4 100644
--- a/include/theme.h
+++ b/include/theme.h
@@ -142,6 +142,7 @@ struct theme {
 
 	int osd_workspace_switcher_boxes_width;
 	int osd_workspace_switcher_boxes_height;
+	int osd_workspace_switcher_boxes_border_width;
 
 	struct theme_snapping_overlay
 		snapping_overlay_region, snapping_overlay_edge;
diff --git a/src/theme.c b/src/theme.c
index c987ad2d..34b4d4a1 100644
--- a/src/theme.c
+++ b/src/theme.c
@@ -551,6 +551,7 @@ theme_builtin(struct theme *theme, struct server *server)
 
 	theme->osd_workspace_switcher_boxes_width = 20;
 	theme->osd_workspace_switcher_boxes_height = 20;
+	theme->osd_workspace_switcher_boxes_border_width = 2;
 
 	/* inherit settings in post_processing() if not set elsewhere */
 	theme->osd_bg_color[0] = FLT_MIN;
@@ -903,6 +904,11 @@ entry(struct theme *theme, const char *key, const char *value)
 			get_int_if_positive(
 				value, "osd.workspace-switcher.boxes.height");
 	}
+	if (match_glob(key, "osd.workspace-switcher.boxes.border.width")) {
+		theme->osd_workspace_switcher_boxes_border_width =
+			get_int_if_positive(
+				value, "osd.workspace-switcher.boxes.border.width");
+	}
 	if (match_glob(key, "osd.label.text.color")) {
 		parse_hexstr(value, theme->osd_label_text_color);
 	}
diff --git a/src/workspaces.c b/src/workspaces.c
index ec7106e1..14ed51a9 100644
--- a/src/workspaces.c
+++ b/src/workspaces.c
@@ -120,7 +120,8 @@ _osd_update(struct server *server)
 					.width = rect_width,
 					.height = rect_height,
 				};
-				draw_cairo_border(cairo, fbox, 2);
+				draw_cairo_border(cairo, fbox,
+					theme->osd_workspace_switcher_boxes_border_width);
 				if (active) {
 					cairo_rectangle(cairo, x, margin,
 						rect_width, rect_height);