diff --git a/src/Psalm/CallMap.php b/src/Psalm/CallMap.php
index 41288039e..c241b1b16 100644
--- a/src/Psalm/CallMap.php
+++ b/src/Psalm/CallMap.php
@@ -5343,7 +5343,7 @@ return [
 'ini_get' => ['string|false', 'varname'=>'string'],
 'ini_get_all' => ['array', 'extension='=>'?string', 'details='=>'bool'],
 'ini_restore' => ['void', 'varname'=>'string'],
-'ini_set' => ['string|false', 'varname'=>'string', 'newvalue'=>'string|int|float|bool'],
+'ini_set' => ['string|false', 'varname'=>'string', 'newvalue'=>'string'],
 'inotify_add_watch' => ['int', 'inotify_instance'=>'resource', 'pathname'=>'string', 'mask'=>'int'],
 'inotify_init' => ['resource'],
 'inotify_queue_len' => ['int', 'inotify_instance'=>'resource'],
diff --git a/src/Psalm/Checker/FunctionChecker.php b/src/Psalm/Checker/FunctionChecker.php
index 7f95ac8b1..3b0bea870 100644
--- a/src/Psalm/Checker/FunctionChecker.php
+++ b/src/Psalm/Checker/FunctionChecker.php
@@ -494,6 +494,11 @@ class FunctionChecker extends FunctionLikeChecker
             case 'strrpos':
             case 'stripos':
             case 'strripos':
+            case 'strstr':
+            case 'stristr':
+            case 'strrchr':
+            case 'strpbrk':
+            case 'array_search':
                 break;
 
             default:
diff --git a/src/psalm.php b/src/psalm.php
index 676118f10..fad4f135d 100644
--- a/src/psalm.php
+++ b/src/psalm.php
@@ -77,9 +77,9 @@ array_map(
 $options = getopt(implode('', $valid_short_options), $valid_long_options);
 
 if (!array_key_exists('use-ini-defaults', $options)) {
-    ini_set('display_errors', 1);
-    ini_set('display_startup_errors', 1);
-    ini_set('memory_limit', 4 * 1024 * 1024 * 1024);
+    ini_set('display_errors', '1');
+    ini_set('display_startup_errors', '1');
+    ini_set('memory_limit', (string) (4 * 1024 * 1024 * 1024));
 }
 
 if (array_key_exists('help', $options)) {
diff --git a/src/psalter.php b/src/psalter.php
index ccbbc5b86..ba056139b 100644
--- a/src/psalter.php
+++ b/src/psalter.php
@@ -7,8 +7,8 @@ use Psalm\IssueBuffer;
 
 // show all errors
 error_reporting(-1);
-ini_set('display_errors', 1);
-ini_set('display_startup_errors', 1);
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
 ini_set('memory_limit', '2048M');
 
 // get options from command line
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 55d15f200..84687b5dd 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,7 +1,7 @@
 <?php
 
-ini_set('display_startup_errors', 1);
-ini_set('html_errors', 1);
+ini_set('display_startup_errors', '1');
+ini_set('html_errors', '1');
 ini_set('memory_limit', '-1');
 error_reporting(E_ALL);