--- freem/configure.ac	2025/04/09 20:06:02	1.24
+++ freem/configure.ac	2025/04/09 21:10:14	1.25
@@ -1,5 +1,5 @@
 #
-#   $Id: configure.ac,v 1.24 2025/04/09 20:06:02 snw Exp $
+#   $Id: configure.ac,v 1.25 2025/04/09 21:10:14 snw Exp $
 #    autoconf rules for FreeM
 #
 #  
@@ -24,6 +24,9 @@
 #   along with FreeM.  If not, see <https://www.gnu.org/licenses/>.
 #
 #   $Log: configure.ac,v $
+#   Revision 1.25  2025/04/09 21:10:14  snw
+#   Only use -Wno-format-truncation et al when the compiler supports them
+#
 #   Revision 1.24  2025/04/09 20:06:02  snw
 #   Add macros to check for compiler flags to suppress unavoidable warnings
 #
@@ -94,8 +97,8 @@ AC_CONFIG_HEADERS([src/config.h])
 AC_CONFIG_MACRO_DIR([m4])
 
 AX_LIB_READLINE
-AX_CHECK_COMPILE_FLAG([-Wno-format-truncation])
-AX_CHECK_COMPILE_FLAG([-Wno-format-contains-nul])
+AX_CHECK_COMPILE_FLAG([-Wno-format-truncation], [AX_APPEND_FLAG([-Wno-format-truncation])])
+AX_CHECK_COMPILE_FLAG([-Wno-format-contains-nul], [AX_APPEND_FLAG([-Wno-format-contains-nul])])
 
 # check for libm
 AC_CHECK_LIB([m], [powf])