diff --git a/perl-DateTime-Format-HTTP.spec b/perl-DateTime-Format-HTTP.spec
index 3eb49d7..1fcbc2e 100644
--- a/perl-DateTime-Format-HTTP.spec
+++ b/perl-DateTime-Format-HTTP.spec
@@ -10,6 +10,7 @@ Source0: http://search.cpan.org/CPAN/authors/id/D/DR/DROLSKY/DateTime-Format-HTT
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
 BuildArch:      noarch
+BuildRequires:  perl(Class::ISA)
 BuildRequires:  perl(DateTime) >= 0.17
 BuildRequires:  perl(HTTP::Date) => 1.44
 BuildRequires:  perl(Test::More) >= 0.47