diff --git a/zlib-ada.spec b/zlib-ada.spec
index f6d2de1..5ae9de2 100644
--- a/zlib-ada.spec
+++ b/zlib-ada.spec
@@ -18,7 +18,7 @@ Source3:        zlib_ada.gpr
 
 BuildRequires:  gcc-gnat fedora-gnat-project-common zlib-devel chrpath
 # Build only on architectures where gcc-gnat is available:
-ExclusiveArch:  %{GNAT_arches}
+ExclusiveArch:  %{ix86} x86_64 ia64 ppc ppc64 alpha
 
 %global common_description_en \
 Zlib-Ada is a thick Ada binding to the popular compression/decompression \