--- configure.ac.orig	2020-01-24 10:55:31.703758000 -0500
+++ configure.ac	2020-01-24 10:56:51.768604000 -0500
@@ -4472,12 +4472,18 @@
 		;;
 	macppc-*-openbsd* | powerpc*-*-linux* | powerpc-*-openbsd* | \
         powerpc-*-sysv* | powerpc-*-darwin* | powerpc-*-netbsd* | \
-        powerpc-*-freebsd* | powerpc*-*-aix* | powerpc*-*-os400* )
+        powerpc*-*-freebsd* | powerpc*-*-aix* | powerpc*-*-os400* )
 		if test "x$ac_cv_sizeof_void_p" = "x8"; then
 			TARGET=POWERPC64;
 			CPPFLAGS="$CPPFLAGS -D__mono_ppc__ -D__mono_ppc64__"
+			# mono#18554 - be more robust in testing for -mminimal-toc
+			AC_MSG_NOTICE([Checking for -mminimal-toc])
 			if ! (echo $CC | grep -q -- 'clang'); then
-				CFLAGS="$CFLAGS -mminimal-toc"
+				AX_CHECK_COMPILE_FLAG(
+					[-mminimal-toc],
+					[CFLAGS="$CFLAGS -mminimal-toc"],
+					[CFLAGS="$CFLAGS"]
+				)
 			fi
 		else
 			TARGET=POWERPC;