diff --git a/python-rsa.spec b/python-rsa.spec
index 72add2e..ab97882 100644
--- a/python-rsa.spec
+++ b/python-rsa.spec
@@ -29,6 +29,7 @@ BuildRequires:  python-pyasn1 >= 0.1.3
 BuildRequires:  python3-devel
 BuildRequires:  python3-setuptools
 BuildRequires:  python3-pyasn1 >= 0.1.3
+BuildRequires:  python3-unittest2
 %endif # with_python3
 
 %description