diff --git a/build.gradle b/build.gradle
index 5ba3f45e9b12804b04b2f8baf5ac5bd0c639c45b..a664f1f94cad424396080a20049d32158160634c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,8 +8,8 @@ buildscript {
     }
 
     dependencies {
-        classpath 'org.freemarker:freemarker:2.3.29'
-        classpath 'org.yaml:snakeyaml:1.25'
+        classpath 'org.freemarker:freemarker:2.3.30'
+        classpath 'org.yaml:snakeyaml:1.27'
     }
 }
 
@@ -34,10 +34,7 @@ dependencies {
     asciidoctor 'org.asciidoctor:asciidoctorj-epub3:1.5.0-alpha.9'
     asciidoctor 'org.asciidoctor:asciidoctorj-pdf:1.5.0-beta.8'
     
-    // asciidoctor-bibtex requires a 4.x version of bibtex-ruby, but for some reason the build installs a 5.x version by default.
-    // To fix this we need this manual dependency on a 4.x version of bibtex-ruby.
-    gems 'rubygems:bibtex-ruby:4.4.7'
-    gems 'rubygems:asciidoctor-bibtex:0.6.0'
+    gems 'rubygems:asciidoctor-bibtex:0.8.0'
 }
 
 asciidoctorj {