diff --git a/bridge/build.gradle b/bridge/build.gradle
index f1234f9850..d2a0d01b41 100644
--- a/bridge/build.gradle
+++ b/bridge/build.gradle
@@ -82,7 +82,7 @@ dependencies {
     // JAnsi: for drawing things to the terminal in nicely coloured ways.
     compile "org.fusesource.jansi:jansi:$jansi_version"
 
-    compile "commons-lang:commons-lang:2.6"
+    compile "commons-lang:commons-lang:$commons_lang_version"
     
     integrationTestCompile project(':node-driver')
     integrationTestCompile "org.apache.curator:curator-test:${curator_version}"
diff --git a/build.gradle b/build.gradle
index 6fd3838406..f24c896583 100644
--- a/build.gradle
+++ b/build.gradle
@@ -78,6 +78,7 @@ buildscript {
     ext.class_graph_version = '4.2.12'
     ext.jcabi_manifests_version = '1.1'
     ext.picocli_version = '3.8.0'
+    ext.commons_lang_version = '2.6'
 
     // Name of the IntelliJ SDK created for the deterministic Java rt.jar.
     // ext.deterministic_idea_sdk = '1.8 (Deterministic)'
diff --git a/core/build.gradle b/core/build.gradle
index 93603e2300..da6913b4ee 100644
--- a/core/build.gradle
+++ b/core/build.gradle
@@ -100,7 +100,7 @@ dependencies {
     // Apache JEXL: An embeddable expression evaluation library.
     // This may be temporary until we experiment with other ways to do on-the-fly contract specialisation via an API.
     compile "org.apache.commons:commons-jexl3:3.0"
-    compile 'commons-lang:commons-lang:2.6'
+    compile "commons-lang:commons-lang:$commons_lang_version"
 
     // Java ed25519 implementation. See https://github.com/str4d/ed25519-java/
     compile "net.i2p.crypto:eddsa:$eddsa_version"