diff --git a/build/autoconf/arch.m4 b/build/autoconf/arch.m4
index b62ea71..53179a7 100644
--- a/build/autoconf/arch.m4
+++ b/build/autoconf/arch.m4
@@ -215,7 +215,7 @@ if test "$CPU_ARCH" = "arm"; then
 
   AC_MSG_CHECKING(ARM version support in compiler)
   dnl Determine the target ARM architecture (5 for ARMv5, v5T, v5E, etc.; 6 for ARMv6, v6K, etc.)
-  ARM_ARCH=`${CC-cc} ${CFLAGS} -dM -E - < /dev/null | sed -n 's/.*__ARM_ARCH_\([[0-9]][[0-9]]*\).*/\1/p'`
+  ARM_ARCH=`${CC-cc} ${CFLAGS} -dM -E - < /dev/null | sed -n 's/.*__ARM_ARCH_\([[0-9]][[0-9]]*\).*/\1/p' | head -n 1`
   AC_MSG_RESULT("$ARM_ARCH")
 
   AC_MSG_CHECKING(for ARM NEON support in compiler)
