diff --git a/docs/build.gradle b/docs/build.gradle
index fa92cb706..d9cfc97dc 100644
--- a/docs/build.gradle
+++ b/docs/build.gradle
@@ -24,7 +24,7 @@ asciidoctor {
     asciidoctorj {
         modules {
             diagram.use()
-            diagram.version '2.2.4'
+            diagram.version '2.2.14'  // https://github.com/asciidoctor/asciidoctorj-diagram/releases/
         }
     }
 }
@@ -34,7 +34,7 @@ asciidoctor.doFirst {
 }
 
 asciidoctorj {
-    version = '2.3.0'
+    version = '2.5.11'  // https://github.com/asciidoctor/asciidoctorj/releases
 }
 
 asciidoctor.dependsOn cleanUserGuide
diff --git a/docs/userguide/004_What_to_Check.adoc b/docs/userguide/004_What_to_Check.adoc
index 737ae5aef..f3078f4d9 100644
--- a/docs/userguide/004_What_to_Check.adoc
+++ b/docs/userguide/004_What_to_Check.adoc
@@ -86,6 +86,7 @@ classes().that().haveNameMatching(".*Bar")
 ----
 @startuml
 hide empty members
+set separator none
 skinparam componentStyle uml2
 
 skinparam component {
@@ -158,6 +159,7 @@ classes().that().implement(Connection.class)
 ----
 @startuml
 hide empty members
+set separator none
 skinparam componentStyle uml2
 
 skinparam component {
@@ -235,6 +237,7 @@ classes().that().areAssignableTo(EntityManager.class)
 ----
 @startuml
 hide empty members
+set separator none
 skinparam componentStyle uml2
 
 skinparam component {
@@ -292,6 +295,7 @@ layeredArchitecture()
 ----
 @startuml
 hide empty members
+set separator none
 skinparam componentStyle uml2
 
 skinparam component {
diff --git a/docs/userguide/008_The_Library_API.adoc b/docs/userguide/008_The_Library_API.adoc
index c019bfa0e..4a3aeab37 100644
--- a/docs/userguide/008_The_Library_API.adoc
+++ b/docs/userguide/008_The_Library_API.adoc
@@ -59,6 +59,7 @@ More precisely, the following holds:
 ----
 @startuml
 hide empty members
+set separator none
 skinparam componentStyle uml2
 
 skinparam class {