diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php
index 3c1034df2db..f4258e56cab 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php
@@ -44,11 +44,15 @@
 use function array_merge;
 use function array_values;
 use function count;
+use function filter_var;
 use function in_array;
+use function is_numeric;
 use function is_string;
 use function preg_match;
+use function trim;
 
 use const PHP_INT_MAX;
+use const FILTER_VALIDATE_INT;
 
 /**
  * @internal
@@ -237,6 +241,33 @@ public static function analyze(
         return true;
     }
 
+    /**
+     * @param string|int $literal_array_key
+     * @return false|int
+     */
+    public static function getLiteralArrayKeyInt(
+        $literal_array_key
+    ) {
+        if (!is_numeric($literal_array_key)) {
+            return false;
+        }
+
+        // PHP 8 values with whitespace after number are counted as numeric
+        // and filter_var treats them as such too
+        // ensures that '15 ' will stay '15 '
+        if (trim($literal_array_key) !== $literal_array_key) {
+            return false;
+        }
+
+        // '+5' will pass the filter_var check but won't be changed in keys
+        if ($literal_array_key[0] === '+') {
+            return false;
+        }
+
+        // e.g. 015 is numeric but won't be typecast as it's not a valid int
+        return filter_var($literal_array_key, FILTER_VALIDATE_INT);
+    }
+
     private static function analyzeArrayItem(
         StatementsAnalyzer $statements_analyzer,
         Context $context,
diff --git a/src/Psalm/Internal/Type/TypeParser.php b/src/Psalm/Internal/Type/TypeParser.php
index f79cc3cfdc8..30558a837fc 100644
--- a/src/Psalm/Internal/Type/TypeParser.php
+++ b/src/Psalm/Internal/Type/TypeParser.php
@@ -7,6 +7,7 @@
 use Psalm\Codebase;
 use Psalm\Exception\TypeParseTreeException;
 use Psalm\Internal\Analyzer\ProjectAnalyzer;
+use Psalm\Internal\Analyzer\Statements\Expression\ArrayAnalyzer;
 use Psalm\Internal\Type\ParseTree\CallableParamTree;
 use Psalm\Internal\Type\ParseTree\CallableTree;
 use Psalm\Internal\Type\ParseTree\CallableWithReturnTypeTree;
@@ -86,7 +87,6 @@
 use function defined;
 use function end;
 use function explode;
-use function filter_var;
 use function get_class;
 use function in_array;
 use function is_int;
@@ -100,9 +100,6 @@
 use function strtolower;
 use function strtr;
 use function substr;
-use function trim;
-
-use const FILTER_VALIDATE_INT;
 
 /**
  * @psalm-suppress InaccessibleProperty Allowed during construction
@@ -669,11 +666,8 @@ private static function getTypeFromGenericTree(
             }
 
             foreach ($generic_params[0]->getAtomicTypes() as $key => $atomic_type) {
-                // PHP 8 values with whitespace after number are counted as numeric
-                // and filter_var treats them as such too
                 if ($atomic_type instanceof TLiteralString
-                    && ($string_to_int = filter_var($atomic_type->value, FILTER_VALIDATE_INT)) !== false
-                    && trim($atomic_type->value) === $atomic_type->value
+                    && ($string_to_int = ArrayAnalyzer::getLiteralArrayKeyInt($atomic_type->value)) !== false
                 ) {
                     $builder = $generic_params[0]->getBuilder();
                     $builder->removeType($key);