diff --git a/src/Analyser/TypeSpecifier.php b/src/Analyser/TypeSpecifier.php
index 4ea8a595f5..99a816e1b6 100644
--- a/src/Analyser/TypeSpecifier.php
+++ b/src/Analyser/TypeSpecifier.php
@@ -929,6 +929,18 @@ public function specifyTypesInCondition(
 						);
 					} else {
 						$varType = $scope->getType($var->var);
+
+						if ($varType->isArray()->yes() && count($dimType->getConstantScalarTypes()) <= 1) {
+							$types = $types->unionWith(
+								$this->create(
+									$var->var,
+									new NonEmptyArrayType(),
+									$context,
+									$scope,
+								)->setRootExpr($expr),
+							);
+						}
+
 						$narrowedKey = AllowedArrayKeysTypes::narrowOffsetKeyType($varType, $dimType);
 						if ($narrowedKey !== null) {
 							$types = $types->unionWith(
diff --git a/tests/PHPStan/Analyser/nsrt/bug-12274.php b/tests/PHPStan/Analyser/nsrt/bug-12274.php
index b17b11aed8..c22fcc2d72 100644
--- a/tests/PHPStan/Analyser/nsrt/bug-12274.php
+++ b/tests/PHPStan/Analyser/nsrt/bug-12274.php
@@ -40,7 +40,7 @@ function getItemsByModifiedIndex(array $items): array
 function testKeepListAfterIssetIndex(array $list, int $i): void
 {
 	if (isset($list[$i])) {
-		assertType('list<int>', $list);
+		assertType('non-empty-list<int>', $list);
 		$list[$i] = 21;
 		assertType('non-empty-list<int>', $list);
 		$list[$i+1] = 21;
@@ -53,8 +53,8 @@ function testKeepListAfterIssetIndex(array $list, int $i): void
 function testKeepNestedListAfterIssetIndex(array $nestedList, int $i, int $j): void
 {
 	if (isset($nestedList[$i][$j])) {
-		assertType('list<list<int>>', $nestedList);
-		assertType('list<int>', $nestedList[$i]);
+		assertType('non-empty-list<list<int>>', $nestedList);
+		assertType('non-empty-list<int>', $nestedList[$i]);
 		$nestedList[$i][$j] = 21;
 		assertType('non-empty-list<list<int>>', $nestedList);
 		assertType('list<int>', $nestedList[$i]);
@@ -66,7 +66,7 @@ function testKeepNestedListAfterIssetIndex(array $nestedList, int $i, int $j): v
 function testKeepListAfterIssetIndexPlusOne(array $list, int $i): void
 {
 	if (isset($list[$i])) {
-		assertType('list<int>', $list);
+		assertType('non-empty-list<int>', $list);
 		$list[$i+1] = 21;
 		assertType('non-empty-list<int>', $list);
 	}
@@ -77,7 +77,7 @@ function testKeepListAfterIssetIndexPlusOne(array $list, int $i): void
 function testKeepListAfterIssetIndexOnePlus(array $list, int $i): void
 {
 	if (isset($list[$i])) {
-		assertType('list<int>', $list);
+		assertType('non-empty-list<int>', $list);
 		$list[1+$i] = 21;
 		assertType('non-empty-list<int>', $list);
 	}
@@ -90,7 +90,7 @@ function testShouldLooseListbyAst(array $list, int $i): void
 	if (isset($list[$i])) {
 		$i++;
 
-		assertType('list<int>', $list);
+		assertType('non-empty-list<int>', $list);
 		$list[1+$i] = 21;
 		assertType('non-empty-array<int<0, max>, int>', $list);
 	}
@@ -101,7 +101,7 @@ function testShouldLooseListbyAst(array $list, int $i): void
 function testShouldLooseListbyAst2(array $list, int $i): void
 {
 	if (isset($list[$i])) {
-		assertType('list<int>', $list);
+		assertType('non-empty-list<int>', $list);
 		$list[2+$i] = 21;
 		assertType('non-empty-array<int<0, max>, int>', $list);
 	}
diff --git a/tests/PHPStan/Analyser/nsrt/bug-13674.php b/tests/PHPStan/Analyser/nsrt/bug-13674.php
new file mode 100644
index 0000000000..cabbb99632
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-13674.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Bug13674a;
+
+use function assert;
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	/**
+	 * @param array<int> $arrayA
+	 * @param list<int> $listA
+	 */
+	public function sayHello($arrayA, $listA, int $i): void
+	{
+		if (isset($arrayA[$i])) {
+			assertType('non-empty-array<int>', $arrayA);
+		} else {
+			assertType('array<int>', $arrayA);
+		}
+		assertType('array<int>', $arrayA);
+
+		if (isset($listA[$i])) {
+			assertType('non-empty-list<int>', $listA);
+		} else {
+			assertType('list<int>', $listA);
+		}
+		assertType('list<int>', $listA);
+
+		if (!isset($listA[$i])) {
+			assertType('list<int>', $listA);
+			return;
+		}
+		assertType('non-empty-list<int>', $listA);
+
+		$emptyArray = [];
+		assertType('false', isset($emptyArray[$i]));
+	}
+}
diff --git a/tests/PHPStan/Analyser/nsrt/has-offset-type-bug.php b/tests/PHPStan/Analyser/nsrt/has-offset-type-bug.php
index eacfb06af6..09955bde2e 100644
--- a/tests/PHPStan/Analyser/nsrt/has-offset-type-bug.php
+++ b/tests/PHPStan/Analyser/nsrt/has-offset-type-bug.php
@@ -26,7 +26,7 @@ public function doFoo(array $errorMessages): void
 				continue;
 			}
 
-			assertType('array<string, int<1, max>>', $fileErrorsCounts);
+			assertType('non-empty-array<string, int<1, max>>', $fileErrorsCounts);
 			assertType('int<1, max>', $fileErrorsCounts[$errorMessage]);
 
 			$fileErrorsCounts[$errorMessage]++;
diff --git a/tests/PHPStan/Analyser/nsrt/specified-types-closure-use.php b/tests/PHPStan/Analyser/nsrt/specified-types-closure-use.php
index 9cd49e4522..f5f8189ded 100644
--- a/tests/PHPStan/Analyser/nsrt/specified-types-closure-use.php
+++ b/tests/PHPStan/Analyser/nsrt/specified-types-closure-use.php
@@ -48,10 +48,10 @@ function ($arr) use ($key): void {
 	public function doBuzz(array $arr, string $key): void
 	{
 		if (isset($arr[$key])) {
-			assertType('array', $arr);
+			assertType('non-empty-array', $arr);
 			assertType("mixed~null", $arr[$key]);
 			function () use ($arr, $key): void {
-				assertType('array', $arr);
+				assertType('non-empty-array', $arr);
 				assertType("mixed~null", $arr[$key]);
 			};
 		}
@@ -60,10 +60,10 @@ function () use ($arr, $key): void {
 	public function doBuzz(array $arr, string $key): void
 	{
 		if (isset($arr[$key])) {
-			assertType('array', $arr);
+			assertType('non-empty-array', $arr);
 			assertType("mixed~null", $arr[$key]);
 			function ($key) use ($arr): void {
-				assertType('array', $arr);
+				assertType('non-empty-array', $arr);
 				assertType("mixed", $arr[$key]);
 			};
 		}
diff --git a/tests/PHPStan/Rules/Arrays/data/bug-11679.php b/tests/PHPStan/Rules/Arrays/data/bug-11679.php
index 463362516a..c2badb5b75 100644
--- a/tests/PHPStan/Rules/Arrays/data/bug-11679.php
+++ b/tests/PHPStan/Rules/Arrays/data/bug-11679.php
@@ -33,7 +33,7 @@ public function sayHello(int $index): bool
 			$this->arr[$index]['foo'] = true;
 			assertType('non-empty-array<int, array{foo: true}>', $this->arr);
 		}
-		assertType('array<int, array{foo?: bool}>', $this->arr);
+		assertType('non-empty-array<int, array{foo?: bool}>', $this->arr);
 		return $this->arr[$index]['foo']; // PHPStan does not realize 'foo' is set
 	}
 }
diff --git a/tests/PHPStan/Rules/Variables/IssetRuleTest.php b/tests/PHPStan/Rules/Variables/IssetRuleTest.php
index 40b837c134..3cacd9c7f5 100644
--- a/tests/PHPStan/Rules/Variables/IssetRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/IssetRuleTest.php
@@ -498,7 +498,7 @@ public function testPr4374(): void
 
 		$this->analyse([__DIR__ . '/data/pr-4374.php'], [
 			[
-				'Offset string on array<PR4374\Foo> in isset() always exists and is not nullable.',
+				'Offset string on non-empty-array<PR4374\Foo> in isset() always exists and is not nullable.',
 				23,
 			],
 		]);
diff --git a/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php b/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
index 318bd3b275..2f8c90da34 100644
--- a/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
@@ -285,7 +285,7 @@ public function testBug7190(): void
 	{
 		$this->analyse([__DIR__ . '/../Properties/data/bug-7190.php'], [
 			[
-				'Offset int on array<int, int> on left side of ?? always exists and is not nullable.',
+				'Offset int on non-empty-array<int, int> on left side of ?? always exists and is not nullable.',
 				20,
 			],
 		]);