diff --git a/lib/private/Files/Storage/Common.php b/lib/private/Files/Storage/Common.php
index d58042b042c39..696232da64fa0 100644
--- a/lib/private/Files/Storage/Common.php
+++ b/lib/private/Files/Storage/Common.php
@@ -97,11 +97,15 @@ public function is_file(string $path): bool {
 	}
 
 	public function filesize(string $path): int|float|false {
-		if ($this->is_dir($path)) {
-			return 0; //by definition
+		$type = $this->filetype($path);
+		if ($type === false) {
+			return false;
+		}
+		if ($type !== 'file') {
+			return 0;
 		} else {
 			$stat = $this->stat($path);
-			return isset($stat['size']) ? $stat['size'] : 0;
+			return $stat['size'] ?? 0;
 		}
 	}
 
diff --git a/lib/private/Files/Storage/Local.php b/lib/private/Files/Storage/Local.php
index a27489ce7b6ba..e3afc6bd01702 100644
--- a/lib/private/Files/Storage/Local.php
+++ b/lib/private/Files/Storage/Local.php
@@ -218,7 +218,7 @@ public function getMetaData(string $path): ?array {
 	}
 
 	public function filetype(string $path): string|false {
-		$filetype = filetype($this->getSourcePath($path));
+		$filetype = @filetype($this->getSourcePath($path));
 		if ($filetype === 'link') {
 			$filetype = filetype(realpath($this->getSourcePath($path)));
 		}
@@ -226,7 +226,11 @@ public function filetype(string $path): string|false {
 	}
 
 	public function filesize(string $path): int|float|false {
-		if (!$this->is_file($path)) {
+		$type = $this->filetype($path);
+		if ($type === false) {
+			return false;
+		}
+		if ($type !== 'file') {
 			return 0;
 		}
 		$fullPath = $this->getSourcePath($path);
diff --git a/tests/lib/Files/Storage/Storage.php b/tests/lib/Files/Storage/Storage.php
index 60e696739eed5..9107d99cd6738 100644
--- a/tests/lib/Files/Storage/Storage.php
+++ b/tests/lib/Files/Storage/Storage.php
@@ -311,6 +311,8 @@ public function testStat(): void {
 
 		$this->instance->unlink('/lorem.txt');
 		$this->assertTrue($this->instance->hasUpdated('/', $mtimeStart - 5));
+
+		$this->assertFalse($this->instance->filesize('/non-existing-file.txt'));
 	}
 
 	/**