diff --git a/psalm.xml b/psalm.xml
index a7e6106..1179766 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -18,5 +18,6 @@
         <UndefinedFunction errorLevel="suppress"/>
         <UndefinedClass errorLevel="suppress"/>
         <UndefinedDocblockClass errorLevel="suppress"/>
+        <UndefinedConstant errorLevel="suppress"/>
     </issueHandlers>
 </psalm>
diff --git a/src/Formatter/Backtrace_Formatter.php b/src/Formatter/Backtrace_Formatter.php
index b89738d..202599e 100644
--- a/src/Formatter/Backtrace_Formatter.php
+++ b/src/Formatter/Backtrace_Formatter.php
@@ -76,12 +76,12 @@ class Backtrace_Formatter {
 	}
 
 	/**
+	 *
+	 * @psalm-suppress PossiblyFalseOperand
 	 *
 	 * @param string $item Backtrace item.
 	 *
 	 * @return string
-	 *
-	 * @psalm-suppress PossiblyFalseOperand
 	 */
 	protected function shorten_include( string $item ): string {
 
diff --git a/src/Mustache_Cache_FrozenCache.php b/src/Mustache_Cache_FrozenCache.php
index 08427c3..1eb8449 100644
--- a/src/Mustache_Cache_FrozenCache.php
+++ b/src/Mustache_Cache_FrozenCache.php
@@ -11,12 +11,12 @@ class Mustache_Cache_FrozenCache extends \Mustache_Cache_FilesystemCache {
 	/**
 	 * Cache and load a compiled Mustache_Template class.
 	 *
+	 * @psalm-suppress InvalidScalarArgument
+	 *
 	 * @param string $key   Key.
 	 * @param string $value Value.
 	 *
 	 * @return void
-	 *
-	 * @psalm-suppress InvalidScalarArgument
 	 */
 	public function cache( $key, $value ): void {
 
diff --git a/src/Record/Collector/Http_Collector.php b/src/Record/Collector/Http_Collector.php
index cc31f58..1baaa06 100644
--- a/src/Record/Collector/Http_Collector.php
+++ b/src/Record/Collector/Http_Collector.php
@@ -61,9 +61,7 @@ class Http_Collector extends Stopwatch_Collector {
 	 * @param array           $args     HTTP request arguments.
 	 * @param string          $url      The request URL.
 	 *
-	 * @return mixed
-	 *
-	 * @noinspection MoreThanThreeArgumentsInspection
+	 * @return array|\WP_Error
 	 */
 	public function http_api_debug( $response, string $type, $class, array $args, string $url ) {
 
diff --git a/src/Record/Collector/Plugin_Load_Collector.php b/src/Record/Collector/Plugin_Load_Collector.php
index 22f8d95..f4bdf08 100644
--- a/src/Record/Collector/Plugin_Load_Collector.php
+++ b/src/Record/Collector/Plugin_Load_Collector.php
@@ -31,6 +31,8 @@ class Plugin_Load_Collector implements Record_Collector_Interface {
 	 * Records time for a plugin that just finished loading.
 	 *
 	 * @param string $plugin Plugin file path.
+	 *
+	 * @psalm-suppress DocblockTypeContradiction
 	 */
 	public function plugin_loaded( $plugin ): void {