diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFillReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFillReturnTypeProvider.php
index b367f4111..14fafda68 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFillReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFillReturnTypeProvider.php
@@ -23,24 +23,39 @@ class ArrayFillReturnTypeProvider implements \Psalm\Plugin\EventHandler\Function
         }
 
         $first_arg_type = isset($call_args[0]) ? $statements_source->node_data->getType($call_args[0]->value) : null;
+        $second_arg_type = isset($call_args[1]) ? $statements_source->node_data->getType($call_args[1]->value) : null;
         $third_arg_type = isset($call_args[2]) ? $statements_source->node_data->getType($call_args[2]->value) : null;
 
-        if ($third_arg_type) {
-            if ($first_arg_type
-                && $first_arg_type->isSingleIntLiteral()
-                && $first_arg_type->getSingleIntLiteral()->value === 0
+        $value_type_from_third_arg = $third_arg_type ? clone $third_arg_type : Type::getMixed();
+
+        if ($first_arg_type
+            && $first_arg_type->isSingleIntLiteral()
+            && $first_arg_type->getSingleIntLiteral()->value === 0
+        ) {
+            if ($second_arg_type
+                && self::isPositiveNumericType($second_arg_type)
             ) {
                 return new Type\Union([
                     new Type\Atomic\TNonEmptyList(
-                        clone $third_arg_type
+                        $value_type_from_third_arg
                     )
                 ]);
             }
 
             return new Type\Union([
-                new Type\Atomic\TArray([
+                new Type\Atomic\TList(
+                    $value_type_from_third_arg
+                )
+            ]);
+        }
+
+        if ($second_arg_type
+            && self::isPositiveNumericType($second_arg_type)
+        ) {
+            return new Type\Union([
+                new Type\Atomic\TNonEmptyArray([
                     Type::getInt(),
-                    clone $third_arg_type
+                    $value_type_from_third_arg,
                 ])
             ]);
         }
@@ -48,8 +63,16 @@ class ArrayFillReturnTypeProvider implements \Psalm\Plugin\EventHandler\Function
         return new Type\Union([
             new Type\Atomic\TArray([
                 Type::getInt(),
-                Type::getMixed()
+                $value_type_from_third_arg,
             ])
         ]);
     }
+
+    private static function isPositiveNumericType (Type\Union $arg): bool {
+        if ($arg->isSingle() && $arg->hasPositiveInt()) {
+            return true;
+        }
+
+        return $arg->isSingleIntLiteral() && $arg->getSingleIntLiteral()->value > 0;
+    }
 }
diff --git a/tests/ArrayFunctionCallTest.php b/tests/ArrayFunctionCallTest.php
index ebeac5ded..32e1f6c30 100644
--- a/tests/ArrayFunctionCallTest.php
+++ b/tests/ArrayFunctionCallTest.php
@@ -909,6 +909,10 @@ class ArrayFunctionCallTest extends TestCase
                         return "a";
                     }',
             ],
+            'arrayFillZeroLength' => [
+                '<?php
+                    count(array_fill(0, 0, 0)) === 0;',
+            ],
             'implodeMultiDimensionalArray' => [
                 '<?php
                     $urls = array_map("implode", [["a", "b"]]);',
@@ -1953,6 +1957,11 @@ class ArrayFunctionCallTest extends TestCase
                     array_filter(["hello"], "foo");',
                 'error_message' => 'InvalidScalarArgument',
             ],
+            'arrayFillPositiveConstantLength' => [
+                '<?php
+                    count(array_fill(0, 1, 0)) === 0;',
+                'error_message' => 'TypeDoesNotContainType'
+            ],
             'arrayFilterTooFewArgs' => [
                 '<?php
                     function foo(int $i, string $s) : bool {