diff --git a/boost.yaml b/boost.yaml
index ba17266..d8a6ca1 100644
--- a/boost.yaml
+++ b/boost.yaml
@@ -26,11 +26,11 @@ data:
         tracker: https://github.com/modularity-modules/boost
     dependencies:
         buildrequires:
-            bootstrap: master
+            bootstrap: f27
         requires:
-            platform: master
-            python2: master
-            python3: master
+            platform: f27
+            python2: 2.7
+            python3: 3.6
     profiles:
         development:
             rpms:
@@ -102,19 +102,19 @@ data:
         rpms:
             python-nose:
                 rationale: A dependency of numpy
-                ref: master
+                ref: f27
                 buildorder: 1
             openblas:
                 rationale: A dependency of numpy
-                ref: master
+                ref: f27
                 buildorder: 1
             numpy:
                 rationale: A dependency of boost-numpy
-                ref: master
+                ref: f27
                 buildorder: 9
             boost:
                 rationale: The free peer-reviewed portable C++ source libraries
-                ref: master
+                ref: f27
                 buildorder: 10