diff --git a/Dockerfile b/Dockerfile
index adb29586..86c3d089 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ ARG asciidoctor_version=2.0.15
 ARG asciidoctor_confluence_version=0.0.2
 ARG asciidoctor_pdf_version=1.5.4
 ARG asciidoctor_diagram_version=2.1.2
-ARG asciidoctor_epub3_version=1.5.0.alpha.19
+ARG asciidoctor_epub3_version=1.5.1
 ARG asciidoctor_fb2_version=0.5.1
 ARG asciidoctor_mathematical_version=0.3.5
 ARG asciidoctor_revealjs_version=4.1.0
diff --git a/tests/env_vars.yml b/tests/env_vars.yml
index cbe1ee0f..587b8c37 100644
--- a/tests/env_vars.yml
+++ b/tests/env_vars.yml
@@ -4,7 +4,7 @@ ASCIIDOCTOR_VERSION: 2.0.15
 ASCIIDOCTOR_CONFLUENCE_VERSION: 0.0.2
 ASCIIDOCTOR_PDF_VERSION: 1.5.4
 ASCIIDOCTOR_DIAGRAM_VERSION: 2.1.2
-ASCIIDOCTOR_EPUB3_VERSION: 1.5.0.alpha.19
+ASCIIDOCTOR_EPUB3_VERSION: 1.5.1
 ASCIIDOCTOR_FB2_VERSION: 0.5.1
 ASCIIDOCTOR_MATHEMATICAL_VERSION: 0.3.5
 ASCIIDOCTOR_REVEALJS_VERSION: 4.1.0