diff --git a/scalapack.spec b/scalapack.spec
index 60353bd..538bee0 100644
--- a/scalapack.spec
+++ b/scalapack.spec
@@ -12,7 +12,8 @@
   %bcond_without mpich
 %endif
 
-%ifarch x86_64 %{ix86} armv7hl %{power64} aarch64
+%{!?openblas_arches:%global openblas_arches x86_64 %{ix86} armv7hl %{power64} aarch64}
+%ifarch %{openblas_arches}
 # matches openblas ExclusiveArch
 %bcond_without openblas
 %endif