diff --git a/src/sysprof/style.css b/src/sysprof/style.css
index 752d73c7..ea75b44d 100644
--- a/src/sysprof/style.css
+++ b/src/sysprof/style.css
@@ -95,3 +95,7 @@ timescrubber timecode {
 flamegraph {
   font-size: 11px;
 }
+
+timespanlayer {
+  font-size: 10px;
+}
diff --git a/src/sysprof/sysprof-time-span-layer.c b/src/sysprof/sysprof-time-span-layer.c
index d20842c6..6ffd228b 100644
--- a/src/sysprof/sysprof-time-span-layer.c
+++ b/src/sysprof/sysprof-time-span-layer.c
@@ -497,6 +497,8 @@ sysprof_time_span_layer_class_init (SysprofTimeSpanLayerClass *klass)
                          (G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_properties (object_class, N_PROPS, properties);
+
+  gtk_widget_class_set_css_name (widget_class, "timespanlayer");
 }
 
 static void