diff --git a/src/main/java/org/apache/commons/math/optimization/fitting/PolynomialFitter.java b/src/main/java/org/apache/commons/math/optimization/fitting/PolynomialFitter.java
index 192119598..aef64253f 100644
--- a/src/main/java/org/apache/commons/math/optimization/fitting/PolynomialFitter.java
+++ b/src/main/java/org/apache/commons/math/optimization/fitting/PolynomialFitter.java
@@ -61,6 +61,7 @@ public class PolynomialFitter {
 
     /**
      * Remove all observations.
+     * @since 2.2
      */
     public void clearObservations() {
         fitter.clearObservations();