diff --git a/src/Php/Generator/TypeCheckGenerator.php b/src/Php/Generator/TypeCheckGenerator.php
index 1c8e4843..ce7ac739 100644
--- a/src/Php/Generator/TypeCheckGenerator.php
+++ b/src/Php/Generator/TypeCheckGenerator.php
@@ -126,6 +126,10 @@ trait TypeCheckGenerator
         }
 
         $varName = $argInfo->name;
+        if ($argInfo->variadic) {
+            return $this->genUnionVariadicParamCheck($argInfo, $argIndex);
+        }
+
         $conditions = [];
         foreach ($argInfo->typeCheck as $entry) {
             $cond = $this->genSingleTypeCondition($varName, $entry);
@@ -138,10 +142,7 @@ trait TypeCheckGenerator
         }
 
         $orExpr = implode(' || ', $conditions);
-        $fnName = $this->functionDef->getNamespacedName();
-        $msgExpr = 'php::concat(php::concat(php::Str(' . $this->genCharPtr($fnName, true) . ' "(): Argument #' . ($argIndex + 1)
-                 . ' ($' . $varName . ') must be of type " ' . $this->genCharPtr($argInfo->typeStr, true) . ' ", "), '
-                 . $varName . '.typeStr()), php::Str(" given"))';
+        $msgExpr = $this->genUnionParamTypeErrorExpr($argInfo, $varName, (string) ($argIndex + 1));
 
         $code = $this->getIndent() . 'if (UNEXPECTED(!(' . $orExpr . '))) {' . PHP_EOL;
         $this->indentLevel++;
@@ -152,6 +153,55 @@ trait TypeCheckGenerator
         return $code;
     }
 
+    protected function genUnionVariadicParamCheck(ArgInfo $argInfo, int $argIndex): string
+    {
+        $valueVar = $this->genTmpVarName();
+        $iterVar = $this->genTmpVarName();
+        $argNoVar = $this->genTmpVarName();
+
+        $conditions = [];
+        foreach ($argInfo->typeCheck as $entry) {
+            $cond = $this->genSingleTypeCondition($valueVar, $entry);
+            if ($cond !== '') {
+                $conditions[] = $cond;
+            }
+        }
+        if (empty($conditions)) {
+            return '';
+        }
+
+        $orExpr = implode(' || ', $conditions);
+        $msgExpr = $this->genUnionParamTypeErrorExpr($argInfo, $valueVar, $argNoVar);
+
+        $code = $this->getIndent() . 'for (auto ' . $iterVar . ' = ' . $argInfo->name . '.begin(); ' . $iterVar . ' != ' . $argInfo->name . '.end(); ++' . $iterVar . ') {' . PHP_EOL;
+        $this->indentLevel++;
+        $code .= $this->getIndent() . self::TYPE_VAR . ' ' . $valueVar . ' = ' . $iterVar . '.value();' . PHP_EOL;
+        $code .= $this->getIndent() . self::TYPE_INT . ' ' . $argNoVar . ' = ' . ($argIndex + 1) . ' + ' . $iterVar . '.index();' . PHP_EOL;
+        $code .= $this->getIndent() . 'if (UNEXPECTED(!(' . $orExpr . '))) {' . PHP_EOL;
+        $this->indentLevel++;
+        $code .= $this->getIndent() . 'php::throwException(zend_ce_type_error, (' . $msgExpr . ').toCString());' . PHP_EOL;
+        $this->indentLevel--;
+        $code .= $this->getIndent() . '}' . PHP_EOL;
+        $this->indentLevel--;
+        $code .= $this->getIndent() . '}' . PHP_EOL;
+
+        return $code;
+    }
+
+    protected function genUnionParamTypeErrorExpr(ArgInfo $argInfo, string $valueExpr, string $argNoExpr): string
+    {
+        $fnName = $this->functionDef->getNamespacedName();
+        return 'php::concat({'
+            . 'php::Str(' . $this->genCharPtr($fnName . '(): Argument #', true) . '), '
+            . 'php::toString(' . $argNoExpr . '), '
+            . 'php::Str(' . $this->genCharPtr(' ($' . $argInfo->name . ') must be of type ', true) . '), '
+            . 'php::Str(' . $this->genCharPtr($argInfo->typeStr, true) . '), '
+            . 'php::Str(", "), '
+            . $valueExpr . '.typeStr(), '
+            . 'php::Str(" given")'
+            . '})';
+    }
+
     protected function genUnionReturnCheck(string $varName): string
     {
         $typeCheck = $this->functionDef->returnTypeCheck;
diff --git a/src/gen_stub.php b/src/gen_stub.php
index 5aaaa0cd..3565b900 100755
--- a/src/gen_stub.php
+++ b/src/gen_stub.php
@@ -868,9 +868,15 @@ class ArgInfo {
                     !$this->isVariadic ? ", " . $this->getDefaultValueAsArginfoString() : ""
                 );
             }
+            if ($this->isVariadic) {
+                return sprintf(
+                    "\tZEND_ARG_VARIADIC_TYPE_INFO(%s, %s, IS_MIXED, 0)\n",
+                    $this->sendBy, $this->name
+                );
+            }
             return sprintf(
-                "\tZEND_%s_TYPE_MASK(%s, %s, %s, %s)\n",
-                $argKind, $this->sendBy, $this->name,
+                "\tZEND_ARG_TYPE_MASK(%s, %s, %s, %s)\n",
+                $this->sendBy, $this->name,
                 $arginfoType->toTypeMask(),
                 $this->getDefaultValueAsArginfoString()
             );
diff --git a/tests/aot/type_decl/variadic-union-param-check.phpt b/tests/aot/type_decl/variadic-union-param-check.phpt
new file mode 100644
index 00000000..0ad7a0d7
--- /dev/null
+++ b/tests/aot/type_decl/variadic-union-param-check.phpt
@@ -0,0 +1,55 @@
+--TEST--
+Variadic union and nullable parameter runtime type checking
+--FILE--
+<?php
+function collect_scalars(int|string ...$values): array
+{
+    return $values;
+}
+
+function collect_nullable(?int ...$values): array
+{
+    return $values;
+}
+
+function main(): void
+{
+    var_dump(collect_scalars(1, "two", named: 3));
+    var_dump(collect_nullable(1, null, 3));
+
+    $errors = [];
+    try {
+        collect_scalars(1, "two", []);
+    } catch (\TypeError $e) {
+        $errors[] = $e->getMessage();
+    }
+    try {
+        collect_nullable(ok: 1, bad: "x");
+    } catch (\TypeError $e) {
+        $errors[] = $e->getMessage();
+    }
+
+    foreach ($errors as $error) {
+        var_dump($error);
+    }
+}
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  int(1)
+  [1]=>
+  string(3) "two"
+  ["named"]=>
+  int(3)
+}
+array(3) {
+  [0]=>
+  int(1)
+  [1]=>
+  NULL
+  [2]=>
+  int(3)
+}
+string(80) "collect_scalars(): Argument #3 ($values) must be of type int|string, array given"
+string(76) "collect_nullable(): Argument #2 ($values) must be of type ?int, string given"