diff --git a/src/Client/TrapHandle.php b/src/Client/TrapHandle.php
index 8ee17295..003e8e4b 100644
--- a/src/Client/TrapHandle.php
+++ b/src/Client/TrapHandle.php
@@ -31,7 +31,13 @@ public static function fromArray(array $array): self
     public function if(bool|callable $condition): self
     {
         if (\is_callable($condition)) {
-            $condition = $condition();
+            try {
+                $condition = (bool)$condition();
+            } catch (\Throwable $e) {
+                $this->values[] = $e;
+
+                return $this;
+            }
         }
 
         $this->haveToSend = $condition;
@@ -106,6 +112,10 @@ private function sendDump(): void
         }
 
         // Dump sequence of values
+        /**
+         * @var string|int $key
+         * @var mixed $value
+         */
         foreach ($this->values as $key => $value) {
             /** @psalm-suppress TooManyArguments */
             VarDumper::dump($value, label: $key, depth: $this->depth);
diff --git a/src/Client/TrapHandle/ContextProvider/Source.php b/src/Client/TrapHandle/ContextProvider/Source.php
index 001fb68d..146413db 100644
--- a/src/Client/TrapHandle/ContextProvider/Source.php
+++ b/src/Client/TrapHandle/ContextProvider/Source.php
@@ -1,7 +1,5 @@
 <?php
 
-declare(strict_types=1);
-
 namespace Buggregator\Trap\Client\TrapHandle\ContextProvider;
 
 use Buggregator\Trap\Client\TrapHandle\StackTrace;
@@ -18,6 +16,11 @@
  * @author Nicolas Grekas <p@tchwork.com>
  * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
  *
+ * @link https://github.com/symfony/var-dumper/blob/7.0/Dumper/ContextProvider/SourceContextProvider.php
+ * @link https://github.com/symfony/var-dumper/blob/6.3/Dumper/ContextProvider/SourceContextProvider.php
+ *
+ * @psalm-suppress all
+ *
  * todo: rewrite and decompose
  */
 final class Source implements ContextProviderInterface
@@ -27,6 +30,9 @@ final class Source implements ContextProviderInterface
     private ?string $projectDir;
     private ?FileLinkFormatter $fileLinkFormatter;
 
+    /**
+     * @psalm-suppress UndefinedClass
+     */
     public function __construct(string $charset = null, string $projectDir = null, FileLinkFormatter $fileLinkFormatter = null, int $limit = 9)
     {
         $this->charset = $charset;
diff --git a/src/Client/TrapHandle/Counter.php b/src/Client/TrapHandle/Counter.php
index 42920389..9c3f8644 100644
--- a/src/Client/TrapHandle/Counter.php
+++ b/src/Client/TrapHandle/Counter.php
@@ -6,18 +6,20 @@
 
 final class Counter
 {
-    /** @var array<non-empty-string, int<0, max>> */
+    /** @var array<string, int<0, max>> */
     private static array $counters = [];
 
     /**
      * Returns true if the counter of related stack trace is less than $times. In this case, the counter is incremented.
+     *
+     * @param int<0, max> $times
      */
     public static function checkAndIncrement(string $key, int $times): bool
     {
         self::$counters[$key] ??= 0;
 
         if (self::$counters[$key] < $times) {
-            self::$counters[$key]++;
+            ++self::$counters[$key];
             return true;
         }
 
diff --git a/src/Client/TrapHandle/Dumper.php b/src/Client/TrapHandle/Dumper.php
index 22e2ff08..678f2abd 100644
--- a/src/Client/TrapHandle/Dumper.php
+++ b/src/Client/TrapHandle/Dumper.php
@@ -22,33 +22,35 @@
 /**
  * @internal
  * @psalm-internal Buggregator\Trap\Client
- * @psalm-type DumperHandler = Closure(mixed $var, string|int|null $label, int $depth): void
  */
 final class Dumper
 {
-    /** @var DumperHandler|null */
+    /** @var null|Closure(mixed, string|null, int): mixed */
     private static ?Closure $handler;
 
-    public static function dump(mixed $var, string|int|null $label = null, int $depth = 0)
+    public static function dump(mixed $var, string|int|null $label = null, int $depth = 0): mixed
     {
-        return (self::$handler ??= self::registerHandler())($var, $label, $depth);
+        return (self::$handler ??= self::registerHandler())($var, empty($label) ? null : (string)$label, $depth);
     }
 
     /**
-     * @return DumperHandler|null The previous handler if any
+     * @return null|callable(mixed, string|null, int): mixed
+     * @psalm-suppress MixedInferredReturnType, MixedPropertyTypeCoercion, MismatchingDocblockReturnType
      */
     public static function setHandler(callable $callable = null): ?Closure
     {
-        return ([$callable, self::$handler] = [self::$handler, $callable(...)])[0];
+        return ([$callable, self::$handler] = [self::$handler, $callable === null ? null : $callable(...)])[0];
     }
 
     /**
-     * @return DumperHandler
+     * @return Closure(mixed, string|null, int): mixed
+     *
      * @author Nicolas Grekas <p@tchwork.com>
      */
     private static function registerHandler(): Closure
     {
         $cloner = new VarCloner();
+        /** @psalm-suppress InvalidArgument */
         $cloner->addCasters(ReflectionCaster::UNSET_CLOSURE_FILE_INFO);
 
         $format = $_SERVER['VAR_DUMPER_FORMAT'] ?? null;
@@ -73,19 +75,22 @@ private static function registerHandler(): Closure
             $dumper = new ContextualizedDumper($dumper, [new SourceContextProvider()]);
         }
 
-        return self::$handler = static function ($var, string|int|null $label = null, int $depth = 0) use ($cloner, $dumper): void {
+        return self::$handler = static function (mixed $var, string|null $label = null, int $depth = 0)
+        use ($cloner, $dumper): ?string {
             $var = $cloner->cloneVar($var);
 
             $label === null or $var = $var->withContext(['label' => $label]);
             $depth > 0 and $var = $var->withMaxDepth($depth);
 
-            $dumper->dump($var);
+            return $dumper->dump($var);
         };
     }
 
     /**
      * @return array<array-key, ContextProviderInterface> The context providers
      * @author Nicolas Grekas <p@tchwork.com>
+     *
+     * @psalm-suppress UndefinedClass
      */
     private static function getContextProviders(): array
     {
@@ -93,11 +98,15 @@ private static function getContextProviders(): array
 
         if (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true) && \class_exists(Request::class)) {
             $requestStack = new RequestStack();
+            /** @psalm-suppress MixedMethodCall */
             $requestStack->push(Request::createFromGlobals());
             $contextProviders['request'] = new RequestContextProvider($requestStack);
         }
 
-        $fileLinkFormatter = \class_exists(FileLinkFormatter::class) ? new FileLinkFormatter(null, $requestStack ?? null) : null;
+        /** @var null|FileLinkFormatter $fileLinkFormatter */
+        $fileLinkFormatter = \class_exists(FileLinkFormatter::class)
+            ? new FileLinkFormatter(null, $requestStack ?? null)
+            : null;
 
         return $contextProviders + [
                 'cli' => new CliContextProvider(),
diff --git a/src/Client/TrapHandle/StackTrace.php b/src/Client/TrapHandle/StackTrace.php
index 3d82a554..24e3d613 100644
--- a/src/Client/TrapHandle/StackTrace.php
+++ b/src/Client/TrapHandle/StackTrace.php
@@ -4,20 +4,18 @@
 
 namespace Buggregator\Trap\Client\TrapHandle;
 
-use Buggregator\Trap\Client\TrapHandle;
-
 final class StackTrace
 {
     /**
      * @param string $baseDir Base directory for relative paths
-     * @return array<string, array{
-     *     function?: non-empty-string,
-     *     line?: int<0, max>,
-     *     file?: non-empty-string,
+     * @return list<array{
+     *     function?: string,
+     *     line?: int,
+     *     file?: string,
      *     class?: class-string,
      *     object?: object,
-     *     type?: non-empty-string,
-     *     args?: array
+     *     type?: string,
+     *     args?: list<mixed>
      * }>
      */
     public static function stackTrace(string $baseDir = ''): array
diff --git a/src/functions.php b/src/functions.php
index 1850597e..713171b9 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -19,6 +19,7 @@
      */
     function trap(mixed ...$values): TrapHandle
     {
+        /** @psalm-suppress InternalMethod */
         return TrapHandle::fromArray($values);
     }
 } catch (\Throwable $e) {