diff --git a/Tests/BenchmarkTests/OperatingSystemAndMallocTests.swift b/Tests/BenchmarkTests/OperatingSystemAndMallocTests.swift
index 9f3d5069..7db61f49 100644
--- a/Tests/BenchmarkTests/OperatingSystemAndMallocTests.swift
+++ b/Tests/BenchmarkTests/OperatingSystemAndMallocTests.swift
@@ -106,7 +106,10 @@ final class OperatingSystemAndMallocTests: XCTestCase {
         let amplificationFactor = 1_000
 
         let tempFile = tmpfile()
-        XCTAssertNotNil(tempFile, "tmpfile() failed: \(errno)")
+        guard let tempFile else {
+            XCTFail("tmpfile() failed: \(errno)")
+            return
+        }
 
         let fildes = fileno(tempFile)