diff --git a/pom.xml b/pom.xml
index 6040f8c..c28838f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -13,7 +13,7 @@
         <pitest.coverage>100</pitest.coverage>
         <pitest.mutation>100</pitest.mutation>
         <junit.version>4.12</junit.version>
-        <assertj.version>3.8.0</assertj.version>
+        <assertj.version>3.9.1</assertj.version>
         <coveralls-maven-plugin.version>4.3.0</coveralls-maven-plugin.version>
         <tiles-maven-plugin.version>2.10</tiles-maven-plugin.version>
         <kemitix-tiles.version>0.5.2</kemitix-tiles.version>