diff --git a/pypy3.spec b/pypy3.spec
index 3c5f5c5..d6bb1dd 100644
--- a/pypy3.spec
+++ b/pypy3.spec
@@ -225,6 +225,7 @@ BuildRequires:  gc-devel
 
 # For use in the selftests, for recording stats:
 BuildRequires:  time
+BuildRequires:  /usr/bin/free
 
 # For use in the selftests, for imposing a per-test timeout:
 BuildRequires:  perl