diff --git a/system-tools.yaml b/system-tools.yaml
index b582091..10f9f26 100644
--- a/system-tools.yaml
+++ b/system-tools.yaml
@@ -14,9 +14,9 @@ data:
       - MIT
   dependencies:
     buildrequires:
-      bootstrap: master
+      bootstrap: f27
     requires:
-      platform: master
+      platform: f27
   references:
     community: https://docs.pagure.org/modularity/
     tracker: https://github.com/modularity-modules/system-tools
@@ -42,16 +42,16 @@ data:
     rpms:
       calc:
         rationale: A command-line calculator.
-        ref: master
+        ref: f27
       dateutils:
         rationale: A command-line utility for date and time calculation.
-        ref: master
+        ref: f27
       gcal:
         rationale: A command-line calendar utility.
-        ref: master
+        ref: f27
       mlocate:
         rationale: A utility for finding files.
-        ref: master
+        ref: f27
       screen:
         rationale: A screen manager supporting multiple logins on one terminal.
-        ref: master
+        ref: f27