diff --git a/config/config.php b/config/config.php
index df957c9..bd134c0 100755
--- a/config/config.php
+++ b/config/config.php
@@ -6,8 +6,6 @@
 return [
     // Default options for our archives
     'archive' => [
-        'zip64' => env('ZIPSTREAM_ENABLE_ZIP64', true),
-
         'predict' => env('ZIPSTREAM_PREDICT_SIZE', true)
     ],
 
diff --git a/src/ZipStream.php b/src/ZipStream.php
index c80c827..64d1e8d 100755
--- a/src/ZipStream.php
+++ b/src/ZipStream.php
@@ -160,15 +160,15 @@ public function getMeta(): Collection
     public function process(): int
     {
         $this->bytesSent = 0;
+        $this->configureZip64();
 
         event(new ZipStreaming($this));
 
-        $this->queue->map->toZipStreamFile($this)->each->process();
-
         $predicted = $this->canPredictZipSize()
             ? $this->predictZipSize()
             : false;
 
+        $this->queue->map->toZipStreamFile($this)->each->process();
         $this->finish();
         $this->getOutputStream()->close();
 
@@ -178,13 +178,23 @@ public function process(): int
 
         event(new ZipStreamed($this));
 
-        if ($predicted && $predicted != $this->getFinalSize()) {
+        if ($predicted !== false && $predicted != $this->getFinalSize()) {
             event(new ZipSizePredictionFailed($this, $predicted, $this->getFinalSize()));
         }
 
         return $this->getFinalSize();
     }
 
+    public function configureZip64()
+    {
+        $this->opt->setEnableZip64(
+            // More than 65535 files
+            count($this->files) > 0xFFFF
+            // Filesize over max 32 bit integer
+            || $this->queue->sum->getFilesize() > 0xFFFFFFFF
+        );
+    }
+
     /**
      * @return StreamedResponse
      */
@@ -324,17 +334,33 @@ public function predictZipSize(): int
             return $this->predictedSize;
         }
 
+        $this->configureZip64();
+        $this->predictedSize = $this->calculateZipSize();
+
+        // It's conceivable that we didn't need Zip64 until the zip headers/decriptors were added.
+        // If so, turn on Zip64 and calculate again.
+        if(!$this->opt->isEnableZip64() && $this->predictedSize > 0xFFFFFFFF) {
+            $this->opt->setEnableZip64(true);
+            $this->predictedSize = $this->calculateZipSize();
+        }
+
+        return $this->predictedSize;
+    }
+
+    /**
+     * @return int
+     */
+    protected function calculateZipSize(): int
+    {
         $this->bytesSent = 0;
         $this->calculateOnly = true;
 
         $this->queue->map->toZipStreamFile($this)->each->calculate();
         $this->finish();
 
-        $this->predictedSize = $this->queue->sum->getFilesize() + $this->getFinalSize();
-
         $this->calculateOnly = false;
 
-        return $this->predictedSize;
+        return $this->queue->sum->getFilesize() + $this->getFinalSize();
     }
 
     /**
diff --git a/src/ZipStreamServiceProvider.php b/src/ZipStreamServiceProvider.php
index d5f08e1..21e5bc2 100755
--- a/src/ZipStreamServiceProvider.php
+++ b/src/ZipStreamServiceProvider.php
@@ -55,7 +55,6 @@ public function provides()
     protected function buildArchiveOptions(array $config)
     {
         return tap(new ArchiveOptions(), function(ArchiveOptions $options) use($config) {
-            $options->setEnableZip64($config['zip64']);
             $options->setZeroHeader(true);
         });
     }
diff --git a/tests/ZipTest.php b/tests/ZipTest.php
index 7a2092b..1afe369 100644
--- a/tests/ZipTest.php
+++ b/tests/ZipTest.php
@@ -29,17 +29,18 @@ public function testSaveZipOutput()
         file_put_contents("/tmp/test2.txt", "this is the second test file for test run $testrun");
 
         /** @var ZipStream $zip */
-        $zip = Zip::create("my.zip", ["/tmp/test1.txt", "/tmp/test2.txt"]);
+        $zip = Zip::create("small.zip", ["/tmp/test1.txt", "/tmp/test2.txt"]);
         $sizePrediction = $zip->predictZipSize();
         $zip->saveTo("/tmp");
 
-        $this->assertTrue(file_exists("/tmp/my.zip"));
-        $this->assertEquals($sizePrediction, filesize("/tmp/my.zip"));
+        $this->assertFalse($zip->opt->isEnableZip64());
+        $this->assertTrue(file_exists("/tmp/small.zip"));
+        $this->assertEquals($sizePrediction, filesize("/tmp/small.zip"));
 
-        $z = zip_open("/tmp/my.zip");
+        $z = zip_open("/tmp/small.zip");
         $this->assertEquals("this is the first test file for test run $testrun", zip_entry_read(zip_read($z)));
 
-        unlink("/tmp/my.zip");
+        unlink("/tmp/small.zip");
     }
 
     public function testSaveZip64Output()
@@ -51,16 +52,17 @@ public function testSaveZip64Output()
         exec('dd if=/dev/zero count=1024 bs=1048576 >/tmp/medfile.txt');
 
         /** @var ZipStream $zip */
-        $zip = Zip::create("my.zip", ["/tmp/test1.txt", "/tmp/test2.txt", "/tmp/bigfile.txt", "/tmp/medfile.txt"]);
+        $zip = Zip::create("large.zip", ["/tmp/test1.txt", "/tmp/test2.txt", "/tmp/bigfile.txt", "/tmp/medfile.txt"]);
         $sizePrediction = $zip->predictZipSize();
         $zip->saveTo("/tmp");
 
-        $this->assertTrue(file_exists("/tmp/my.zip"));
-        $this->assertEquals($sizePrediction, filesize("/tmp/my.zip"));
+        $this->assertTrue($zip->opt->isEnableZip64());
+        $this->assertTrue(file_exists("/tmp/large.zip"));
+        $this->assertEquals($sizePrediction, filesize("/tmp/large.zip"));
 
-        $z = zip_open("/tmp/my.zip");
+        $z = zip_open("/tmp/large.zip");
         $this->assertEquals("this is the first test file for test run $testrun", zip_entry_read(zip_read($z)));
 
-        unlink("/tmp/my.zip");
+        unlink("/tmp/large.zip");
     }
 }
\ No newline at end of file