diff --git a/docs/reference/gtk/gtk3-sections.txt b/docs/reference/gtk/gtk3-sections.txt
index 477bb18d20..95b5557a2a 100644
--- a/docs/reference/gtk/gtk3-sections.txt
+++ b/docs/reference/gtk/gtk3-sections.txt
@@ -5659,6 +5659,7 @@ GTK_STYLE_CLASS_BOTTOM
 GTK_STYLE_CLASS_LEFT
 GTK_STYLE_CLASS_RIGHT
 GTK_STYLE_CLASS_LINKED
+GTK_STYLE_CLASS_ARROW
 GTK_STYLE_REGION_COLUMN
 GTK_STYLE_REGION_COLUMN_HEADER
 GTK_STYLE_REGION_ROW
diff --git a/gtk/gtkstylecontext.h b/gtk/gtkstylecontext.h
index 547d45edd6..0dfb4769c6 100644
--- a/gtk/gtkstylecontext.h
+++ b/gtk/gtkstylecontext.h
@@ -686,6 +686,16 @@ struct _GtkStyleContextClass
  */
 #define GTK_STYLE_CLASS_PULSE "pulse"
 
+/**
+ * GTK_STYLE_CLASS_ARROW:
+ *
+ * A CSS class used when rendering an arrow element.
+ *
+ * Note that #gtk_render_arrow automatically adds this style class
+ * to the style context when rendering an arrow element.
+ */
+#define GTK_STYLE_CLASS_ARROW "arrow"
+
 
 GType gtk_style_context_get_type (void) G_GNUC_CONST;