diff --git a/cf/check-compile-et.m4 b/cf/check-compile-et.m4
index 56a9f7418..e580cbb49 100644
--- a/cf/check-compile-et.m4
+++ b/cf/check-compile-et.m4
@@ -28,7 +28,8 @@ if ${COMPILE_ET} conftest_et.et >/dev/null 2>&1; then
     CPPFLAGS="-I/usr/include/et ${CPPFLAGS}"
   fi
   dnl Check that the `prefix' and `index' directives were honored.
-  AC_RUN_IFELSE([
+  AC_LANG(C)
+  AC_RUN_IFELSE([AC_LANG_SOURCE([
 #include <com_err.h>
 #include <string.h>
 #include "conftest_et.h"
@@ -37,7 +38,7 @@ int main(int argc, char **argv){
 #error compile_et does not handle error_table N M
 #endif
 return (CONFTEST_CODE2 - CONFTEST_CODE1) != 127;}
-  ], [krb_cv_compile_et="yes"],[CPPFLAGS="${save_CPPFLAGS}"],
+  ])], [krb_cv_compile_et="yes"],[CPPFLAGS="${save_CPPFLAGS}"],
   [krb_cv_compile_et="yes" krb_cv_compile_et_cross=yes] )
 fi
 AC_MSG_RESULT(${krb_cv_compile_et})
diff --git a/cf/check-x.m4 b/cf/check-x.m4
index 5d8806c4b..e8f68e823 100644
--- a/cf/check-x.m4
+++ b/cf/check-x.m4
@@ -32,7 +32,8 @@ if test "$no_x" != yes; then
 			done
 		fi
 		LIBS="$ac_save_libs $foo $X_PRE_LIBS -lX11 $X_EXTRA_LIBS"
-		AC_RUN_IFELSE([
+		AC_LANG(C)
+		AC_RUN_IFELSE([AC_LANG_SOURCE([
 		#include <X11/Xlib.h>
 		foo(void)
 		{
@@ -42,7 +43,7 @@ if test "$no_x" != yes; then
 		{
 		return 0;
 		}
-		],krb_cv_sys_x_libs_rpath="$rflag"; krb_cv_sys_x_libs="$foo"; break,:,
+		])],krb_cv_sys_x_libs_rpath="$rflag"; krb_cv_sys_x_libs="$foo"; break,:,
 		krb_cv_sys_x_libs_rpath="" ; krb_cv_sys_x_libs="" ; break)
 	done
 	LIBS="$ac_save_libs"