diff -Naurp wol-0.7.1.orig/m4/getline.m4 wol-0.7.1/m4/getline.m4
--- wol-0.7.1.orig/m4/getline.m4	2004-04-18 03:01:15.000000000 -0700
+++ wol-0.7.1/m4/getline.m4	2020-07-20 07:50:21.000000000 -0700
@@ -16,6 +16,7 @@ AC_DEFUN([AM_FUNC_GETLINE],
     [echo fooN |tr -d '\012'|tr N '\012' > conftest.data
     AC_TRY_RUN([
 #    include <stdio.h>
+#    include <stdlib.h>
 #    include <sys/types.h>
 #    include <string.h>
     int main ()
diff -Naurp wol-0.7.1.orig/m4/malloc.m4 wol-0.7.1/m4/malloc.m4
--- wol-0.7.1.orig/m4/malloc.m4	2004-04-18 03:03:27.000000000 -0700
+++ wol-0.7.1/m4/malloc.m4	2020-07-20 07:49:41.000000000 -0700
@@ -14,7 +14,7 @@ AC_DEFUN([jm_FUNC_MALLOC],
 
  AC_CACHE_CHECK([for working malloc], jm_cv_func_working_malloc,
   [AC_TRY_RUN([
-    char *malloc ();
+    #include <stdlib.h>
     int
     main ()
     {
diff -Naurp wol-0.7.1.orig/m4/realloc.m4 wol-0.7.1/m4/realloc.m4
--- wol-0.7.1.orig/m4/realloc.m4	2004-04-18 03:03:26.000000000 -0700
+++ wol-0.7.1/m4/realloc.m4	2020-07-20 07:49:56.000000000 -0700
@@ -14,7 +14,7 @@ AC_DEFUN([jm_FUNC_REALLOC],
 
  AC_CACHE_CHECK([for working realloc], jm_cv_func_working_realloc,
   [AC_TRY_RUN([
-    char *realloc ();
+    #include <stdlib.h>
     int
     main ()
     {
