diff --git a/Tests/GzipTests.swift b/Tests/GzipTests.swift
index 5f901319..64819095 100644
--- a/Tests/GzipTests.swift
+++ b/Tests/GzipTests.swift
@@ -11,13 +11,13 @@ import SWCompression
 
 class GzipTests: XCTestCase {
 
-    func perform(test testName: String, mtime: Date) {
-        // Loading archive.
+    func header(test testName: String, mtime: Int) {
+        // Load archive.
         guard let archiveData = try? Data(contentsOf: Constants.url(forTest: testName,
-                                                                 withType: "gz"),
-                                       options: .mappedIfSafe) else {
-                                        XCTFail("Failed to load test archive")
-                                        return
+                                                                    withType: "gz"),
+                                          options: .mappedIfSafe) else {
+                                            XCTFail("Failed to load test archive")
+                                            return
         }
 
         // Test GZip header parsing
@@ -27,10 +27,20 @@ class GzipTests: XCTestCase {
         }
 
         XCTAssertEqual(testGzipHeader.compressionMethod, .deflate, "Incorrect compression method")
-        XCTAssertEqual(testGzipHeader.modificationTime, mtime, "Incorrect mtime")
+        XCTAssertEqual(testGzipHeader.modificationTime, Date(timeIntervalSince1970: TimeInterval(mtime)), "Incorrect mtime")
         XCTAssertEqual(testGzipHeader.osType, .unix, "Incorrect os type")
         XCTAssertEqual(testGzipHeader.originalFileName, "\(testName).answer", "Incorrect original file name")
         XCTAssertEqual(testGzipHeader.comment, nil, "Incorrect comment")
+    }
+
+    func unarchive(test testName: String) {
+        // Load archive.
+        guard let archiveData = try? Data(contentsOf: Constants.url(forTest: testName,
+                                                                 withType: "gz"),
+                                       options: .mappedIfSafe) else {
+                                        XCTFail("Failed to load test archive")
+                                        return
+        }
 
         // Test GZip unarchiving.
         let decompressedData = try? GzipArchive.unarchive(archiveData: archiveData)
@@ -56,48 +66,48 @@ class GzipTests: XCTestCase {
     }
 
     func testGzip1() {
-        self.perform(test: "test1",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698300)))
+        self.header(test: "test1", mtime: 1482698300)
+        self.unarchive(test: "test1")
     }
 
     func testGzip2() {
-        self.perform(test: "test2",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698300)))
+        self.header(test: "test2", mtime: 1482698300)
+        self.unarchive(test: "test2")
     }
 
     func testGzip3() {
-        self.perform(test: "test3",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698301)))
+        self.header(test: "test3", mtime: 1482698301)
+        self.unarchive(test: "test3")
     }
 
     func testGzip4() {
-        self.perform(test: "test4",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698301)))
+        self.header(test: "test4", mtime: 1482698301)
+        self.unarchive(test: "test4")
     }
 
     func testGzip5() {
-        self.perform(test: "test5",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698242)))
+        self.header(test: "test5", mtime: 1482698242)
+        self.unarchive(test: "test5")
     }
 
     func testGzip6() {
-        self.perform(test: "test6",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698305)))
+        self.header(test: "test6", mtime: 1482698305)
+        self.unarchive(test: "test6")
     }
 
     func testGzip7() {
-        self.perform(test: "test7",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1482698304)))
+        self.header(test: "test7", mtime: 1482698304)
+        self.unarchive(test: "test7")
     }
 
     func testGzip8() {
-        self.perform(test: "test8",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1483040005)))
+        self.header(test: "test8", mtime: 1483040005)
+        self.unarchive(test: "test8")
     }
 
     func testGzip9() {
-        self.perform(test: "test9",
-                     mtime: Date(timeIntervalSince1970: TimeInterval(1483040005)))
+        self.header(test: "test9", mtime: 1483040005)
+        self.unarchive(test: "test9")
     }