diff --git a/README.md b/README.md
index 6f1d59c..0c18ba1 100644
--- a/README.md
+++ b/README.md
@@ -5,8 +5,8 @@ simdjson_php bindings for the [simdjson project](https://github.com/lemire/simdj
 [![Build Status (Windows)](https://ci.appveyor.com/api/projects/status/github/crazyxman/simdjson_php?svg=true)](https://ci.appveyor.com/project/crazyxman/simdjson-php)
 
 ## Requirement
-- PHP 7 +
-- We support platforms like Linux or macOS
+
+- PHP 7.0+ (The latest php version was 8.2 at the time of writing)
 - Prerequisites: g++ (version 7 or better) or clang++ (version 6 or better), and a 64-bit system with a command-line shell (e.g., Linux, macOS, freeBSD). We also support programming environments like Visual Studio and Xcode, but different steps are needed
 
 ## Installing
@@ -63,27 +63,29 @@ $jsonString = <<<'JSON'
 }
 JSON;
 
-//Check if a JSON string is valid:
+// Check if a JSON string is valid:
 $isValid = simdjson_is_valid($jsonString); //return bool
 var_dump($isValid);  // true
 
-//Parsing a JSON string. similar to the json_decode() function but without the fourth argument
+// Parsing a JSON string. similar to the json_decode() function but without the fourth argument
 try {
-    $parsedJSON = simdjson_decode($jsonString, true, 512); //return array|object|null. "null" string is not a standard json
+    // returns array|stdClass|string|float|int|bool|null.
+    $parsedJSON = simdjson_decode($jsonString, true, 512);
     var_dump($parsedJSON); // PHP array
 } catch (RuntimeException $e) {
     echo "Failed to parse $jsonString: {$e->getMessage()}\n";
 }
 
-//note. "/" is a separator. Can be used as the "key" of the object and the "index" of the array
-//E.g. "Image/Thumbnail/Url" is ok.
-
+// note. "/" is a separator. Can be used as the "key" of the object and the "index" of the array
+// E.g. "/Image/Thumbnail/Url" is recommended starting in simdjson 4.0.0,
+// but "Image/Thumbnail/Url" is accepted for now.
 
-//get the value of a "key" in a json string
-$value = simdjson_key_value($jsonString, "Image/Thumbnail/Url");
+// get the value of a "key" in a json string
+// (before simdjson 4.0.0, the recommended leading "/" had to be omitted)
+$value = simdjson_key_value($jsonString, "/Image/Thumbnail/Url");
 var_dump($value); // string(38) "http://www.example.com/image/481989943"
 
-$value = simdjson_key_value($jsonString, "Image/IDs/4", true);
+$value = simdjson_key_value($jsonString, "/Image/IDs/4", true);
 var_dump($value);
 /*
 array(1) {
@@ -92,12 +94,13 @@ array(1) {
 }
 */
 
-//check if the key exists. return true|false|null. "true" exists, "false" does not exist, "null" string is not a standard json
-$res = simdjson_key_exists($jsonString, "Image/IDs/1");
+// check if the key exists. return true|false|null. "true" exists, "false" does not exist,
+// throws for invalid JSON.
+$res = simdjson_key_exists($jsonString, "/Image/IDs/1");
 var_dump($res) //bool(true)
 
 // count the values
-$res = simdjson_key_count($jsonString, "Image/IDs");
+$res = simdjson_key_count($jsonString, "/Image/IDs");
 var_dump($res) //int(5)
 
 ```
@@ -138,7 +141,8 @@ function simdjson_is_valid(string $json, int $depth = 512) : bool {}
  * @param string $json The JSON string being decoded
  * @param string $key The JSON pointer being requested
  * @param int $depth The maximum nesting depth of the structure being decoded.
- * @param bool $throw_if_uncountable If true, then throw SimdJsonException instead of returning 0 for JSON pointers
+ * @param bool $throw_if_uncountable If true, then throw SimdJsonException instead of
+                                     returning 0 for JSON pointers
                                      to values that are neither objects nor arrays.
  * @return int
  * @throws SimdJsonException for invalid JSON or invalid JSON pointer
diff --git a/package.xml b/package.xml
index 7e08b0d..a6f03a8 100644
--- a/package.xml
+++ b/package.xml
@@ -20,8 +20,8 @@
  -->
  <date>2022-10-19</date>
  <version>
-  <release>4.0.0</release>
-  <api>4.0.0</api>
+  <release>4.0.1dev</release>
+  <api>4.0.1dev</api>
  </version>
  <stability>
   <release>stable</release>
@@ -29,14 +29,7 @@
  </stability>
  <license uri="https://www.apache.org/licenses/LICENSE-2.0.html">Apache 2.0</license>
  <notes>
-* Make the `SIMDJSON_ERR_*` constants case-sensitive in all PHP versions.
-  (The code it was based on was missing the flag needed to mark constants as case sensitive before PHP 8)
-* Fix a bug that prevented using JSON pointer in `simdjson_key_count`, `simdjson_key_exists`, and `simdjson_key_value` with a leading slash https://www.rfc-editor.org/rfc/rfc6901.html.
-
-  This bug was introduced when working around test failures following a change in json pointer validation in the underlying C simdjson library.
-* "" in a JSON pointer continues to refer to the entire document.
-* "/" in a JSON pointer now properly refers to the key that is the empty string.
-* Continue to allow the non-standard omission of the leading "/" for compatibility with earlier PECL releases. This may be deprecated in a subsequent release.
+* Update the README
  </notes>
  <contents>
   <dir name="/">
@@ -125,6 +118,28 @@
  <providesextension>simdjson</providesextension>
  <extsrcrelease/>
  <changelog>
+  <release>
+   <date>2022-10-19</date>
+   <version>
+    <release>4.0.0</release>
+    <api>4.0.0</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <license uri="https://www.apache.org/licenses/LICENSE-2.0.html">Apache 2.0</license>
+   <notes>
+* Make the `SIMDJSON_ERR_*` constants case-sensitive in all PHP versions.
+  (The code it was based on was missing the flag needed to mark constants as case sensitive before PHP 8)
+* Fix a bug that prevented using JSON pointer in `simdjson_key_count`, `simdjson_key_exists`, and `simdjson_key_value` with a leading slash https://www.rfc-editor.org/rfc/rfc6901.html.
+
+  This bug was introduced when working around test failures following a change in json pointer validation in the underlying C simdjson library.
+* "" in a JSON pointer continues to refer to the entire document.
+* "/" in a JSON pointer now properly refers to the key that is the empty string.
+* Continue to allow the non-standard omission of the leading "/" for compatibility with earlier PECL releases. This may be deprecated in a subsequent release.
+   </notes>
+  </release>
   <release>
    <version>
     <release>3.0.0</release>
diff --git a/php_simdjson.h b/php_simdjson.h
index 9d6ce7d..401ab2a 100644
--- a/php_simdjson.h
+++ b/php_simdjson.h
@@ -51,12 +51,13 @@ BEGIN_EXTERN_C()
 extern zend_module_entry simdjson_module_entry;
 #define phpext_simdjson_ptr &simdjson_module_entry
 
-#define PHP_SIMDJSON_VERSION                  "4.0.0"
+#define PHP_SIMDJSON_VERSION                  "4.0.1dev"
 /**
  * PHP_SIMDJSON_VERSION_ID has the same format as PHP_VERSION_ID: Major version * 10000 + Minor version * 100 + Patch version.
  * This is meant for use by PECL extensions that depend on simdjson.
+ * (e.g. 4.5.6dev and 4.5.6 would be 40506)
  */
-#define PHP_SIMDJSON_VERSION_ID               40000
+#define PHP_SIMDJSON_VERSION_ID               40001
 
 #define SIMDJSON_SUPPORT_URL                  "https://github.com/crazyxman/simdjson_php"