diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/BasenameReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/BasenameReturnTypeProvider.php
index 8e11092326e..487f1dcffb4 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/BasenameReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/BasenameReturnTypeProvider.php
@@ -44,7 +44,48 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
         );
 
         if ($evaled_path === null) {
-            return Type::getString();
+            $union = $statements_source->getNodeTypeProvider()->getType($call_args[0]->value);
+            $generic = false;
+            $non_empty = false;
+            if ($union !== null) {
+                foreach ($union->getAtomicTypes() as $atomic) {
+                    if ($atomic instanceof Type\Atomic\TNonFalsyString) {
+                        continue;
+                    }
+
+                    if ($atomic instanceof Type\Atomic\TLiteralString) {
+                        if ($atomic->value === '') {
+                            $generic = true;
+                            break;
+                        }
+
+                        if ($atomic->value === '0') {
+                            $non_empty = true;
+                            continue;
+                        }
+
+                        continue;
+                    }
+
+                    if ($atomic instanceof Type\Atomic\TNonEmptyString) {
+                        $non_empty = true;
+                        continue;
+                    }
+
+                    $generic = true;
+                    break;
+                }
+            }
+
+            if ($union === null || $generic) {
+                return Type::getString();
+            }
+
+            if ($non_empty) {
+                return Type::getNonEmptyString();
+            }
+
+            return Type::getNonFalsyString();
         }
 
         $basename = basename($evaled_path);
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/DirnameReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/DirnameReturnTypeProvider.php
index f6c63c47ac4..ff4fbc54fed 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/DirnameReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/DirnameReturnTypeProvider.php
@@ -9,7 +9,6 @@
 use Psalm\Plugin\EventHandler\FunctionReturnTypeProviderInterface;
 use Psalm\Type;
 use Psalm\Type\Atomic\TLiteralInt;
-use Psalm\Type\Atomic\TNonEmptyString;
 use Psalm\Type\Union;
 
 use function array_values;
@@ -39,6 +38,41 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
         $statements_source = $event->getStatementsSource();
         $node_type_provider = $statements_source->getNodeTypeProvider();
 
+        $union = $node_type_provider->getType($call_args[0]->value);
+        $generic = false;
+        if ($union !== null) {
+            foreach ($union->getAtomicTypes() as $atomic) {
+                if ($atomic instanceof Type\Atomic\TNonFalsyString) {
+                    continue;
+                }
+
+                if ($atomic instanceof Type\Atomic\TLiteralString) {
+                    if ($atomic->value === '') {
+                        $generic = true;
+                        break;
+                    }
+
+                    // 0 will be non-falsy too (.)
+                    continue;
+                }
+
+                if ($atomic instanceof Type\Atomic\TNonEmptyString
+                    || $atomic instanceof Type\Atomic\TEmptyNumeric) {
+                    continue;
+                }
+
+                // generic string is the only other possible case of empty string
+                // which would result in a generic string
+                $generic = true;
+                break;
+            }
+        }
+
+        $fallback_type = Type::getNonFalsyString();
+        if ($union === null || $generic) {
+            $fallback_type = Type::getString();
+        }
+
         $dir_level = 1;
         if (isset($call_args[1])) {
             $type = $node_type_provider->getType($call_args[1]->value);
@@ -49,7 +83,7 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
                     $atomic_type->value > 0) {
                     $dir_level = $atomic_type->value;
                 } else {
-                    return Type::getString();
+                    return $fallback_type;
                 }
             }
         }
@@ -63,17 +97,7 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
         );
 
         if ($evaled_path === null) {
-            $type = $node_type_provider->getType($call_args[0]->value);
-            if ($type !== null && $type->isSingle()) {
-                $atomic_type = array_values($type->getAtomicTypes())[0];
-                if ($atomic_type instanceof TNonEmptyString) {
-                    return Type::getNonEmptyString();
-                }
-            }
-        }
-
-        if ($evaled_path === null) {
-            return Type::getString();
+            return $fallback_type;
         }
 
         $path_to_file = dirname($evaled_path, $dir_level);
diff --git a/tests/ReturnTypeProvider/BasenameTest.php b/tests/ReturnTypeProvider/BasenameTest.php
index 5c624651f69..89ab1562581 100644
--- a/tests/ReturnTypeProvider/BasenameTest.php
+++ b/tests/ReturnTypeProvider/BasenameTest.php
@@ -32,5 +32,25 @@ public function providerValidCodeParse(): iterable
                 '$base===' => 'string',
             ],
         ];
+
+        yield 'basenameOfStringPathReturnsNonEmptyString' => [
+            'code' => '<?php
+                $foo = rand(0, 1) ? "0" : "world";
+                $base = basename($foo);
+            ',
+            'assertions' => [
+                '$base===' => 'non-empty-string',
+            ],
+        ];
+
+        yield 'basenameOfStringPathReturnsNonFalsyString' => [
+            'code' => '<?php
+                $foo = rand(0, 1) ? "hello" : "world";
+                $base = basename($foo);
+            ',
+            'assertions' => [
+                '$base===' => 'non-falsy-string',
+            ],
+        ];
     }
 }
diff --git a/tests/ReturnTypeProvider/DirnameTest.php b/tests/ReturnTypeProvider/DirnameTest.php
index 48dea4d2cca..98d7b40f722 100644
--- a/tests/ReturnTypeProvider/DirnameTest.php
+++ b/tests/ReturnTypeProvider/DirnameTest.php
@@ -49,7 +49,27 @@ public function providerValidCodeParse(): iterable
                 $dir = dirname(uniqid() . "abc", 2);
             ',
             'assertions' => [
-                '$dir===' => 'non-empty-string',
+                '$dir===' => 'non-falsy-string',
+            ],
+        ];
+
+        yield 'dirnameOfNonEmptyShouldBeNonFalsy' => [
+            'code' => '<?php
+                $foo = rand(0, 1) ? "0" : "world";
+                $dir = dirname($foo, 20);
+            ',
+            'assertions' => [
+                '$dir===' => 'non-falsy-string',
+            ],
+        ];
+
+        yield 'dirnameOfEmptyShouldBeString' => [
+            'code' => '<?php
+                $foo = rand(0, 1) ? "" : "world";
+                $dir = dirname($foo, 20);
+            ',
+            'assertions' => [
+                '$dir===' => 'string',
             ],
         ];
     }