diff --git a/doc/src/sgml/array.sgml b/doc/src/sgml/array.sgml
index ce338c770c9..5b8ef5cabe6 100644
--- a/doc/src/sgml/array.sgml
+++ b/doc/src/sgml/array.sgml
@@ -756,10 +756,7 @@ SELECT f1[1][-2][3] AS e1, f1[1][-1][5] AS e2
    If the value written for an element is <literal>NULL</literal> (in any case
    variant), the element is taken to be NULL.  The presence of any quotes
    or backslashes disables this and allows the literal string value
-   <quote>NULL</quote> to be entered.  Also, for backward compatibility with
-   pre-8.2 versions of <productname>PostgreSQL</productname>, the <xref
-   linkend="guc-array-nulls"/> configuration parameter can be turned
-   <literal>off</literal> to suppress recognition of <literal>NULL</literal> as a NULL.
+   <quote>NULL</quote> to be entered.
   </para>
 
   <para>
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index f36fbb60101..e537b3b0043 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11941,32 +11941,6 @@ dynamic_library_path = '/usr/local/lib/postgresql:$libdir'
 
      <variablelist>
 
-     <varlistentry id="guc-array-nulls" xreflabel="array_nulls">
-      <term><varname>array_nulls</varname> (<type>boolean</type>)
-      <indexterm>
-       <primary><varname>array_nulls</varname> configuration parameter</primary>
-      </indexterm>
-      </term>
-      <listitem>
-       <para>
-        This controls whether the array input parser recognizes
-        unquoted <literal>NULL</literal> as specifying a null array element.
-        By default, this is <literal>on</literal>, allowing array values containing
-        null values to be entered.  However, <productname>PostgreSQL</productname> versions
-        before 8.2 did not support null values in arrays, and therefore would
-        treat <literal>NULL</literal> as specifying a normal array element with
-        the string value <quote>NULL</quote>.  For backward compatibility with
-        applications that require the old behavior, this variable can be
-        turned <literal>off</literal>.
-       </para>
-
-       <para>
-        Note that it is possible to create array values containing null values
-        even when this variable is <literal>off</literal>.
-       </para>
-      </listitem>
-     </varlistentry>
-
      <varlistentry id="guc-backslash-quote" xreflabel="backslash_quote">
       <term><varname>backslash_quote</varname> (<type>enum</type>)
       <indexterm><primary>strings</primary><secondary>backslash quotes</secondary></indexterm>
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index ef66182b047..f1f6336e5c8 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -38,11 +38,6 @@
 #include "utils/typcache.h"
 
 
-/*
- * GUC parameter
- */
-bool		Array_nulls = true;
-
 /*
  * Local definitions
  */
@@ -925,7 +920,7 @@ unquoted_element:
 					elembuf->len = dstlen;
 					*srcptr = p;
 					/* Check if it's unquoted "NULL" */
-					if (Array_nulls && !has_escapes &&
+					if (!has_escapes &&
 						pg_strcasecmp(elembuf->data, "NULL") == 0)
 						return ATOK_ELEM_NULL;
 					else
diff --git a/src/backend/utils/misc/guc_parameters.dat b/src/backend/utils/misc/guc_parameters.dat
index c57441f7d98..380679a76c0 100644
--- a/src/backend/utils/misc/guc_parameters.dat
+++ b/src/backend/utils/misc/guc_parameters.dat
@@ -105,13 +105,6 @@
   max => 'INT_MAX / 2',
 },
 
-{ name => 'array_nulls', type => 'bool', context => 'PGC_USERSET', group => 'COMPAT_OPTIONS_PREVIOUS',
-  short_desc => 'Enables input of NULL elements in arrays.',
-  long_desc => 'When turned on, unquoted NULL in an array input value means a null value; otherwise it is taken literally.',
-  variable => 'Array_nulls',
-  boot_val => 'true',
-},
-
 { name => 'authentication_timeout', type => 'int', context => 'PGC_SIGHUP', group => 'CONN_AUTH_AUTH',
   short_desc => 'Sets the maximum allowed time to complete client authentication.',
   flags => 'GUC_UNIT_S',
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e759f06b50f..01f98de8a9f 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -892,7 +892,6 @@
 
 # - Previous PostgreSQL Versions -
 
-#array_nulls = on
 #backslash_quote = safe_encoding        # on, off, or safe_encoding
 #lo_compat_privileges = off
 #quote_all_identifiers = off
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index 88e4f4d70d8..e7ee184034e 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -343,11 +343,6 @@ typedef struct ArrayIteratorData *ArrayIterator;
 	 (a)->xpn.lbound : ARR_LBOUND((ArrayType *) (a)))
 
 
-/*
- * GUC parameter
- */
-extern PGDLLIMPORT bool Array_nulls;
-
 /*
  * prototypes for functions defined in arrayfuncs.c
  */