diff --git a/Dockerfile b/Dockerfile
index b0dace12..2db41ea1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,10 @@
-ARG alpine_version=3.13.5
+ARG alpine_version=3.13.6
 FROM alpine:${alpine_version} AS base
 
 ARG asciidoctor_version=2.0.16
 ARG asciidoctor_confluence_version=0.0.2
 ARG asciidoctor_pdf_version=1.6.1
-ARG asciidoctor_diagram_version=2.2.0
+ARG asciidoctor_diagram_version=2.2.1
 ARG asciidoctor_epub3_version=1.5.1
 ARG asciidoctor_fb2_version=0.5.1
 ARG asciidoctor_mathematical_version=0.3.5
diff --git a/tests/env_vars.yml b/tests/env_vars.yml
index fe0edb43..3fd39fec 100644
--- a/tests/env_vars.yml
+++ b/tests/env_vars.yml
@@ -1,10 +1,10 @@
 ## This file holds the environement variables for the test harness
 # Only key/value at level 0 are allowed
-ALPINE_VERSION: 3.13.5
+ALPINE_VERSION: 3.13.6
 ASCIIDOCTOR_VERSION: 2.0.16
 ASCIIDOCTOR_CONFLUENCE_VERSION: 0.0.2
 ASCIIDOCTOR_PDF_VERSION: 1.6.1
-ASCIIDOCTOR_DIAGRAM_VERSION: 2.2.0
+ASCIIDOCTOR_DIAGRAM_VERSION: 2.2.1
 ASCIIDOCTOR_EPUB3_VERSION: 1.5.1
 ASCIIDOCTOR_FB2_VERSION: 0.5.1
 ASCIIDOCTOR_MATHEMATICAL_VERSION: 0.3.5