diff --git a/configure.ac b/configure.ac
index 8b79117..eb8aae0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -100,7 +100,7 @@ LIBPOSTFIX=
 case "${host_os}" in
   *linux* )
     case "${host_cpu}" in
-      powerpc64 | s390x | x86_64 | sparc64 | aarch64)
+      powerpc64* | s390x | x86_64 | sparc64 | aarch64)
         LIBPOSTFIX="64"
         ;;
     esac