diff --git a/.phan/config.php b/.phan/config.php
new file mode 100644
index 0000000..4250d75
--- /dev/null
+++ b/.phan/config.php
@@ -0,0 +1,97 @@
+<?php
+
+/**
+ * This configuration will be read and overlaid on top of the
+ * default configuration. Command line arguments will be applied
+ * after this file is read.
+ *
+ * @see src/Phan/Config.php
+ * See Config for all configurable options.
+ *
+ * A Note About Paths
+ * ==================
+ *
+ * Files referenced from this file should be defined as
+ *
+ * ```
+ *   Config::projectPath('relative_path/to/file')
+ * ```
+ *
+ * where the relative path is relative to the root of the
+ * project which is defined as either the working directory
+ * of the phan executable or a path passed in via the CLI
+ * '-d' flag.
+ */
+
+// use Phan\Config;
+
+return [
+	// If true, missing properties will be created when
+	// they are first seen. If false, we'll report an
+	// error message.
+	"allow_missing_properties" => false,
+
+	// Allow null to be cast as any type and for any
+	// type to be cast to null.
+	"null_casts_as_any_type" => false,
+
+	// Backwards Compatibility Checking
+	'backward_compatibility_checks' => true,
+
+	// Run a quick version of checks that takes less
+	// time
+	"quick_mode" => false,
+
+	// Only emit critical issues to start with
+	// (0 is low severity, 5 is normal severity, 10 is critical)
+	"minimum_severity" => 10,
+
+	// default false for include path check
+	"enable_include_path_checks" => true,
+	"include_paths" => [
+	],
+	'ignore_undeclared_variables_in_global_scope' => true,
+
+	"file_list" => [
+	],
+
+	// A list of directories that should be parsed for class and
+	// method information. After excluding the directories
+	// defined in exclude_analysis_directory_list, the remaining
+	// files will be statically analyzed for errors.
+	//
+	// Thus, both first-party and third-party code being used by
+	// your application should be included in this list.
+	'directory_list' => [
+		// Change this to include the folders you wish to analyze
+		// (and the folders of their dependencies)
+		'.'
+		// 'www',
+		// To speed up analysis, we recommend going back later and
+		// limiting this to only the vendor/ subdirectories your
+		// project depends on.
+		// `phan --init` will generate a list of folders for you
+		//'www/vendor',
+	],
+
+
+	// A list of directories holding code that we want
+	// to parse, but not analyze
+	"exclude_analysis_directory_list" => [
+		'vendor',
+	],
+	'exclude_file_list' => [
+	],
+
+	// what not to show as problem
+	'suppress_issue_types' => [
+		// 'PhanUndeclaredMethod',
+		'PhanEmptyFile',
+	],
+
+	// Override to hardcode existence and types of (non-builtin) globals in the global scope.
+	// Class names should be prefixed with `\`.
+	//
+	// (E.g. `['_FOO' => '\FooClass', 'page' => '\PageClass', 'userId' => 'int']`)
+	'globals_type_map' => [],
+];
diff --git a/phpstan.neon b/phpstan.neon
index fe0a316..279478d 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -13,10 +13,3 @@ parameters:
 		-
 			message: '#Strict comparison using === between false and true will always evaluate to false.#'
 			path: %currentWorkingDirectory%/test/aws_gift_card_tests.php
-		#- 'error regex'
-		#-
-		#	message: 'error regex'
-		#	path: %currentWorkingDirectory%/www/some/*
-		#	paths:
-		#		- ...
-		#		- ...
diff --git a/src/AWS/AWS.php b/src/AWS/AWS.php
index 427c026..1ab9411 100644
--- a/src/AWS/AWS.php
+++ b/src/AWS/AWS.php
@@ -321,7 +321,7 @@ class AWS
 
 	/**
 	 * @param float $amount
-	 * @param string $creation_id
+	 * @param string|null $creation_id
 	 * @return string
 	 */
 	public function getGiftCardPayload(float $amount, ?string $creation_id = null): string
diff --git a/src/AmazonIncentives.php b/src/AmazonIncentives.php
index 3e5d44e..4cf19f1 100644
--- a/src/AmazonIncentives.php
+++ b/src/AmazonIncentives.php
@@ -54,7 +54,7 @@ final class AmazonIncentives
 
 	/**
 	 * @param float $value
-	 * @param string $creation_request_id AWS creationRequestId
+	 * @param string|null $creation_request_id AWS creationRequestId
 	 * @return                            Response\CreateResponse
 	 *
 	 * @throws AmazonErrors
diff --git a/src/Client/Client.php b/src/Client/Client.php
index c82463e..6002075 100644
--- a/src/Client/Client.php
+++ b/src/Client/Client.php
@@ -55,7 +55,7 @@ class Client implements ClientInterface
 				$error_status = 'RESEND';
 				$error_code = 'T001';
 				$error_type = 'RateExceeded';
-				$message = $result_ar['message'];
+				$message = $result_ar['message'] ?? 'Rate exceeded';
 			} else {
 				// for all other error messages
 				$error_status = $result_ar['agcodResponse']['status'] ?? 'FAILURE';
diff --git a/src/Debug/AmazonDebug.php b/src/Debug/AmazonDebug.php
index 2d767bc..cdc5914 100644
--- a/src/Debug/AmazonDebug.php
+++ b/src/Debug/AmazonDebug.php
@@ -16,7 +16,7 @@ class AmazonDebug
 	 */
 	private static $debug = false;
 	/**
-	 * @var string|null;
+	 * @var string|null
 	 */
 	private static $id = null;
 
@@ -91,7 +91,7 @@ class AmazonDebug
 		if (self::$debug === false) {
 			return;
 		}
-		self::$log[self::getId()][] = $data;
+		self::$log[self::getId() ?? ''][] = $data;
 	}
 
 	/**
diff --git a/test/aws_gift_card_tests.php b/test/aws_gift_card_tests.php
index c51eaeb..936b973 100644
--- a/test/aws_gift_card_tests.php
+++ b/test/aws_gift_card_tests.php
@@ -249,6 +249,7 @@ if ($run_mocks === true) {
 	$mock_ok = '<span style="color:green;">MOCK OK</span>';
 	$mock_failure = '<span style="color:red;">MOCK FAILURE</span>';
 	$mock_value = 500;
+	$mock = [];
 
 	$mock['F0000'] = [ 'ret' => '', 'st' => 'SUCCESS']; // success mock
 	$mock['F1000'] = [ 'ret' => 'F100', 'st' => 'FAILURE']; // SimpleAmountIsNull, etc