diff --git a/CHANGES.txt b/CHANGES.txt
index 8bd8083af..e42da0bcd 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -21,6 +21,7 @@ Fixes
    PR#101 (PR#175).
  * Make the `alpha` attribute of scatter plots work as intended (PR#164).
  * Resume running test for empty container that has been skipped (PR#190).
+ * Improved handling of missing or empty data in scatterplot (PR#210)
 
 Release 4.4.1
 -------------
diff --git a/dev_requirements.txt b/dev_requirements.txt
index abda435a1..a5823e273 100644
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -1,5 +1,6 @@
 --allow-external PIL
 --allow-unverified PIL
+PIL
 unittest2
 coverage
 -e git+http://github.com/enthought/traits.git#egg=traits