diff --git a/acinclude.m4 b/acinclude.m4
index fa2e527f6d1..bd95759a400 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -604,3 +604,22 @@ AC_DEFUN(PHP_DECLARED_TIMEZONE,[
     AC_DEFINE(HAVE_DECLARED_TIMEZONE, 1, [Whether system headers declare timezone])
   fi
 ])
+
+AC_DEFUN(PHP_EBCDIC,[
+  AC_CACHE_CHECK([whether system uses EBCDIC],ac_cv_ebcdic,[
+  AC_TRY_RUN( [
+int main(void) { 
+  return (unsigned char)'A' != (unsigned char)0xC1; 
+} 
+],[
+  ac_cv_ebcdic="yes"
+],[
+  ac_cv_ebcdic="no"
+],[
+  ac_cv_ebcdic="no"
+])])
+  if test "$ac_cv_ebcdic" = "yes"; then
+    AC_DEFINE(CHARSET_EBCDIC,, [Define if system uses EBCDIC])
+  fi
+])
+
diff --git a/configure.in b/configure.in
index a8151a88ade..dfd7aec4f4a 100644
--- a/configure.in
+++ b/configure.in
@@ -153,6 +153,9 @@ if test -n "$PROG_SENDMAIL"; then
   AC_DEFINE(HAVE_SENDMAIL)
 fi
 
+dnl Check whether the system uses EBCDIC (not ASCII) as its native codeset
+PHP_EBCDIC
+
 dnl
 dnl Check for /usr/pkg/{lib,include} which is where NetBSD puts binary
 dnl and source packages.  This should be harmless on other OSs.