diff --git a/composer.json b/composer.json
index 8f5ea655..e459c26b 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
     "require-dev": {
         "wp-cli/entity-command": "^1.3 || ^2 || ^3",
         "wp-cli/extension-command": "^2.0 || ^3",
-        "wp-cli/wp-cli-tests": "^5"
+        "wp-cli/wp-cli-tests": "dev-cached-extension-installs as 5.3.99"
     },
     "config": {
         "process-timeout": 7200,
diff --git a/features/media-image-size.feature b/features/media-image-size.feature
index 2f6fe921..0eed8b90 100644
--- a/features/media-image-size.feature
+++ b/features/media-image-size.feature
@@ -4,7 +4,10 @@ Feature: List image sizes
   Scenario: Basic usage
     Given a WP install
     # Differing themes can have differing default image sizes. Let's stick to one.
-    And I try `wp theme install twentynineteen --activate`
+    And these installed and active themes:
+      """
+      twentynineteen
+      """
 
     When I run `wp media image-size`
     Then STDOUT should be a table containing rows:
@@ -32,7 +35,10 @@ Feature: List image sizes
   Scenario: Basic usage with plugin which registers custom image size
     Given a WP install
     # Differing themes can have differing default image sizes. Let's stick to one.
-    And I try `wp theme install twentynineteen --activate`
+    And these installed and active themes:
+      """
+      twentynineteen
+      """
     And a wp-content/plugins/foo-bar.php file:
       """
       <?php
@@ -82,7 +88,10 @@ Feature: List image sizes
   Scenario: Basic usage (pre-WP-5.3)
     Given a WP install
     # Differing themes can have differing default image sizes. Let's stick to one.
-    And I try `wp theme install twentynineteen --activate`
+    And these installed and active themes:
+      """
+      twentynineteen
+      """
 
     When I run `wp media image-size`
     Then STDOUT should be a table containing rows:
diff --git a/features/media-prune.feature b/features/media-prune.feature
index 84a5de85..30d84f54 100644
--- a/features/media-prune.feature
+++ b/features/media-prune.feature
@@ -2,7 +2,10 @@ Feature: Prune WordPress attachment thumbnails
 
   Background:
     Given a WP install
-    And I try `wp theme install twentynineteen --activate`
+    And these installed and active themes:
+      """
+      twentynineteen
+      """
 
   Scenario: Prune all images while none exists
     When I try `wp media prune --yes`
diff --git a/features/media-regenerate.feature b/features/media-regenerate.feature
index de002d93..cfecc9d4 100644
--- a/features/media-regenerate.feature
+++ b/features/media-regenerate.feature
@@ -2,7 +2,10 @@ Feature: Regenerate WordPress attachments
 
   Background:
     Given a WP install
-    And I try `wp theme install twentynineteen --activate`
+    And these installed and active themes:
+      """
+      twentynineteen
+      """
 
   Scenario: Regenerate all images while none exists
     When I try `wp media regenerate --yes`