diff --git a/plotters/src/chart/dual_coord.rs b/plotters/src/chart/dual_coord.rs
index 048bea02..1d662bcb 100644
--- a/plotters/src/chart/dual_coord.rs
+++ b/plotters/src/chart/dual_coord.rs
@@ -131,11 +131,17 @@ impl<'a, DB: DrawingBackend, CT1: CoordTranslate, CT2: CoordTranslate>
         &self.secondary.drawing_area
     }
 
-    /// Borrow a mutable reference to the chart context that uses the secondary
+    /// Borrow a reference to the chart context that uses the secondary
     /// coordinate system
     pub fn borrow_secondary(&self) -> &ChartContext<'a, DB, CT2> {
         &self.secondary
     }
+
+    /// Borrow a mutable reference to the chart context that uses the secondary
+    /// coordinate system
+    pub fn borrow_secondary_mut(&mut self) -> &mut ChartContext<'a, DB, CT2> {
+        &mut self.secondary
+    }
 }
 
 impl<DB: DrawingBackend, CT1: CoordTranslate, CT2: ReverseCoordTranslate>