diff --git a/perl-DB_File.spec b/perl-DB_File.spec
index 9e8907f..690d2d1 100644
--- a/perl-DB_File.spec
+++ b/perl-DB_File.spec
@@ -80,13 +80,13 @@ for F in t/*.t; do
 done
 
 %build
-perl Makefile.PL INSTALLDIRS=vendor NO_PACKLIST=1 NO_PERLLOCAL=1 OPTIMIZE="$RPM_OPT_FLAGS"
+perl Makefile.PL INSTALLDIRS=vendor NO_PACKLIST=1 NO_PERLLOCAL=1 OPTIMIZE="%{optflags}"
 %{make_build}
 
 %install
 %{make_install}
-find $RPM_BUILD_ROOT -type f -name '*.bs' -size 0 -delete
-%{_fixperms} $RPM_BUILD_ROOT/*
+find %{buildroot} -type f -name '*.bs' -size 0 -delete
+%{_fixperms} %{buildroot}/*
 
 # Install tests
 mkdir -p %{buildroot}%{_libexecdir}/%{name}