diff --git a/graphviz-plugins.spec b/graphviz-plugins.spec
index 6ece65b..a808187 100644
--- a/graphviz-plugins.spec
+++ b/graphviz-plugins.spec
@@ -80,7 +80,7 @@ Patch105:       graphviz-2.18-do_not_use_ocamlopt.patch
 Patch106:       graphviz-fix-pkgIndex.patch
 Requires(pre):  coreutils
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
-Prefix:         /usr
+
 %define rb_libdir    %{_libdir}/ruby
 %define rb_sitedir   %{rb_libdir}/site_ruby/%{rb_ver}
 %define rb_vendordir %{rb_libdir}/vendor_ruby/%{rb_ver}
diff --git a/graphviz.spec b/graphviz.spec
index 9378f81..22f8cb9 100644
--- a/graphviz.spec
+++ b/graphviz.spec
@@ -55,7 +55,6 @@ Requires(pre):  /bin/rm
 Recommends:     graphviz-gd = %{version}
 Recommends:     graphviz-gnome = %{version}
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
-Prefix:         /usr
 
 %description
 A collection of tools and tcl packages for the manipulation and layout