diff --git a/cadc-vodml/build.gradle b/cadc-vodml/build.gradle
index cb5a13af..397c4ab3 100644
--- a/cadc-vodml/build.gradle
+++ b/cadc-vodml/build.gradle
@@ -29,8 +29,8 @@ dependencies {
     compile 'com.helger:ph-schematron:5.6.5'
     compile 'net.sf.saxon:Saxon-HE:[9.8,10)'
 
-    runtime 'org.slf4j:slf4j-api:1.7.30'
-    runtime 'org.slf4j:slf4j-log4j12:1.7.30'
+    runtime 'org.slf4j:slf4j-api:[1.7.30,)'
+    runtime 'org.slf4j:slf4j-ext:[1.7.30,)'
     
     
     testCompile 'junit:junit:4.13'