diff --git a/README.md b/README.md
index c06ae8b..4c7fe38 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,9 @@ uses semantic product versions, and third-party images follow their own tag form
 See the [image revision policy](https://github.com/wodby/images#image-revisions)
 for details.
 
+Test fixtures use `*_IMAGE_REVISION` environment variables for the image release
+suffix.
+
 ## Maintenance
 
 We regularly update images used in this stack and release them together, see [releases page](https://github.com/wodby/docker4ruby/releases) for full changelog and update instructions. Most of routine updates for images and this project performed by [the bot](https://github.com/wodbot) via scripts located at [wodby/images](https://github.com/wodby/images).
diff --git a/tests/.env b/tests/.env
index c3b534e..40b827b 100644
--- a/tests/.env
+++ b/tests/.env
@@ -8,4 +8,4 @@ VALKEY_TAG=9.0-r0
 POSTGRES_TAG=18-r1
 NGINX_TAG=1.31-r1
 
-RUBY_STABILITY_TAG=r0
+RUBY_IMAGE_REVISION=r0
diff --git a/tests/compose.yml b/tests/compose.yml
index 35cbd75..4bb32a9 100644
--- a/tests/compose.yml
+++ b/tests/compose.yml
@@ -10,7 +10,7 @@ services:
     build:
       context: ./
       args:
-        RUBY_TAG: "${RUBY_VER}-dev-${RUBY_STABILITY_TAG}"
+        RUBY_TAG: "${RUBY_VER}-dev-${RUBY_IMAGE_REVISION}"
     environment:
       DEBUG: 1
       DB_HOST: $DB_HOST
@@ -29,7 +29,7 @@ services:
     build:
       context: ./
       args:
-        RUBY_TAG: "${RUBY_VER}-dev-${RUBY_STABILITY_TAG}"
+        RUBY_TAG: "${RUBY_VER}-dev-${RUBY_IMAGE_REVISION}"
     environment:
       DEBUG: 1
       DB_HOST: $DB_HOST