diff --git a/composer.json b/composer.json
index 14771e8..e1b293d 100644
--- a/composer.json
+++ b/composer.json
@@ -15,6 +15,7 @@
         "thecodingmachine/safe": "^1.0 || ^2.0"
     },
     "require-dev": {
+        "nikic/php-parser": "^4",
         "phpunit/phpunit": "^9.6",
         "php-coveralls/php-coveralls": "^2.1",
         "squizlabs/php_codesniffer": "^3.4"
diff --git a/src/Rules/UseSafeFunctionsRule.php b/src/Rules/UseSafeFunctionsRule.php
index d649184..8ba50ac 100644
--- a/src/Rules/UseSafeFunctionsRule.php
+++ b/src/Rules/UseSafeFunctionsRule.php
@@ -19,6 +19,11 @@
  */
 class UseSafeFunctionsRule implements Rule
 {
+    /**
+     * @see JSON_THROW_ON_ERROR
+     */
+    const JSON_THROW_ON_ERROR = 4194304;
+
     public function getNodeType(): string
     {
         return Node\Expr\FuncCall::class;
@@ -33,18 +38,18 @@ public function processNode(Node $node, Scope $scope): array
         $unsafeFunctions = FunctionListLoader::getFunctionList();
 
         if (isset($unsafeFunctions[$functionName])) {
-            if (
-                $functionName === "json_decode"
-                && $this->argValueIncludeJSONTHROWONERROR($node->getArgs()[3] ?? null)
-            ) {
-                return [];
-            }
+            if (! $node->isFirstClassCallable()) {
+                if ($functionName === "json_decode"
+                    && $this->argValueIncludeJSONTHROWONERROR($node->getArgs()[3] ?? null)
+                ) {
+                    return [];
+                }
 
-            if (
-                $functionName === "json_encode"
-                && $this->argValueIncludeJSONTHROWONERROR($node->getArgs()[1] ?? null)
-            ) {
-                return [];
+                if ($functionName === "json_encode"
+                    && $this->argValueIncludeJSONTHROWONERROR($node->getArgs()[1] ?? null)
+                ) {
+                    return [];
+                }
             }
 
             return [new SafeFunctionRuleError($node->name, $node->getStartLine())];
@@ -77,8 +82,7 @@ private function argValueIncludeJSONTHROWONERROR(?Arg $arg): bool
         }
 
         return in_array(true, array_map(function ($element) {
-            // JSON_THROW_ON_ERROR == 4194304
-            return ($element & 4194304) == 4194304;
+            return ($element & self::JSON_THROW_ON_ERROR) == self::JSON_THROW_ON_ERROR;
         }, array_filter($options, function ($element) {
             return is_int($element);
         })), true);
diff --git a/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php b/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php
index 02711e1..fe1ae33 100644
--- a/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php
+++ b/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php
@@ -56,22 +56,17 @@ private function getPreliminarilyResolvedTypeFromFunctionCall(
         Scope $scope
     ): Type {
         $argumentPosition = $this->functions[$functionReflection->getName()];
-        $defaultReturnType = ParametersAcceptorSelector::selectFromArgs(
-            $scope,
-            $functionCall->getArgs(),
-            $functionReflection->getVariants()
-        )
+
+        $args = $functionCall->getArgs();
+        $variants = $functionReflection->getVariants();
+        $defaultReturnType = ParametersAcceptorSelector::selectFromArgs($scope, $args, $variants)
             ->getReturnType();
-        
-        if (count($functionCall->args) <= $argumentPosition) {
-            return $defaultReturnType;
-        }
 
-        $subjectArgument = $functionCall->args[$argumentPosition];
-        if (!$subjectArgument instanceof Arg) {
+        if (count($args) <= $argumentPosition) {
             return $defaultReturnType;
         }
-        
+
+        $subjectArgument = $args[$argumentPosition];
         $subjectArgumentType = $scope->getType($subjectArgument->value);
         $mixedType = new MixedType();
         if ($subjectArgumentType->isSuperTypeOf($mixedType)->yes()) {