diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index 3438aa5a9..bf2686819 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -978,7 +978,7 @@ class Config
         }
 
         if (isset($config_xml['maxStringLength'])) {
-            $attribute_text = intval($config_xml['maxStringLength']);
+            $attribute_text = (int)$config_xml['maxStringLength'];
             $config->max_string_length = $attribute_text;
         }
 
diff --git a/src/Psalm/Internal/Fork/Pool.php b/src/Psalm/Internal/Fork/Pool.php
index 21ef1e432..2facc1111 100644
--- a/src/Psalm/Internal/Fork/Pool.php
+++ b/src/Psalm/Internal/Fork/Pool.php
@@ -307,7 +307,7 @@ class Pool
         // resource id.
         $streams = [];
         foreach ($this->read_streams as $stream) {
-            $streams[intval($stream)] = $stream;
+            $streams[(int)$stream] = $stream;
         }
 
         // Create an array for the content received on each stream,
@@ -340,12 +340,12 @@ class Pool
             foreach ($needs_read as $file) {
                 $buffer = fread($file, 1024);
                 if ($buffer !== false) {
-                    $content[intval($file)] .= $buffer;
+                    $content[(int)$file] .= $buffer;
                 }
 
                 if (strpos($buffer, "\n") !== false) {
-                    $serialized_messages = explode("\n", $content[intval($file)]);
-                    $content[intval($file)] = array_pop($serialized_messages);
+                    $serialized_messages = explode("\n", $content[(int)$file]);
+                    $content[(int)$file] = array_pop($serialized_messages);
 
                     foreach ($serialized_messages as $serialized_message) {
                         $message = unserialize(base64_decode($serialized_message, true));
@@ -375,13 +375,13 @@ class Pool
 
                 // If the stream has closed, stop trying to select on it.
                 if (feof($file)) {
-                    if ($content[intval($file)] !== '') {
+                    if ($content[(int)$file] !== '') {
                         error_log('Child did not send full message before closing the connection');
                         $this->did_have_error = true;
                     }
 
                     fclose($file);
-                    unset($streams[intval($file)]);
+                    unset($streams[(int)$file]);
                 }
             }
         }
diff --git a/src/Psalm/Type/Union.php b/src/Psalm/Type/Union.php
index 50564eaec..9c4bfb74b 100644
--- a/src/Psalm/Type/Union.php
+++ b/src/Psalm/Type/Union.php
@@ -336,7 +336,7 @@ class Union implements TypeNode
                 $printed_int = true;
             }
 
-            $types[] = strval($type);
+            $types[] = (string)$type;
         }
 
         sort($types);
@@ -374,7 +374,7 @@ class Union implements TypeNode
                 $types[] = 'int';
                 $printed_int = true;
             } else {
-                $types[] = strval($type->getKey());
+                $types[] = (string)$type->getKey();
             }
         }
 
@@ -390,7 +390,7 @@ class Union implements TypeNode
 
         $types = [];
         foreach ($this->types as $type) {
-            $types[] = strval($type->getId());
+            $types[] = (string)$type->getId();
         }
         sort($types);