diff --git a/buildSrc/src/main/java/baritone/gradle/task/CreateDistTask.java b/buildSrc/src/main/java/baritone/gradle/task/CreateDistTask.java
index f0d3e547..1b8f1aa5 100644
--- a/buildSrc/src/main/java/baritone/gradle/task/CreateDistTask.java
+++ b/buildSrc/src/main/java/baritone/gradle/task/CreateDistTask.java
@@ -67,7 +67,7 @@ public class CreateDistTask extends BaritoneGradleTask {
         Files.write(getRelativeFile("dist/checksums.txt"), shasum);
     }
 
-    private static String sha1(Path path) {
+    private static synchronized String sha1(Path path) {
         try {
             if (SHA1_DIGEST == null) {
                 SHA1_DIGEST = MessageDigest.getInstance("SHA-1");
diff --git a/buildSrc/src/main/java/baritone/gradle/task/ProguardTask.java b/buildSrc/src/main/java/baritone/gradle/task/ProguardTask.java
index ad0db8cc..06af0011 100644
--- a/buildSrc/src/main/java/baritone/gradle/task/ProguardTask.java
+++ b/buildSrc/src/main/java/baritone/gradle/task/ProguardTask.java
@@ -79,7 +79,7 @@ public class ProguardTask extends BaritoneGradleTask {
             Files.delete(this.artifactUnoptimizedPath);
         }
 
-        Determinizer.main(this.artifactPath.toString(), this.artifactUnoptimizedPath.toString());
+        Determinizer.determinize(this.artifactPath.toString(), this.artifactUnoptimizedPath.toString());
     }
 
     private void downloadProguard() throws Exception {
@@ -197,12 +197,12 @@ public class ProguardTask extends BaritoneGradleTask {
 
     private void proguardApi() throws Exception {
         runProguard(getTemporaryFile(PROGUARD_API_CONFIG));
-        Determinizer.main(this.proguardOut.toString(), this.artifactApiPath.toString());
+        Determinizer.determinize(this.proguardOut.toString(), this.artifactApiPath.toString());
     }
 
     private void proguardStandalone() throws Exception {
         runProguard(getTemporaryFile(PROGUARD_STANDALONE_CONFIG));
-        Determinizer.main(this.proguardOut.toString(), this.artifactStandalonePath.toString());
+        Determinizer.determinize(this.proguardOut.toString(), this.artifactStandalonePath.toString());
     }
 
     private void cleanup() {
@@ -239,8 +239,8 @@ public class ProguardTask extends BaritoneGradleTask {
         this.printOutputLog(p.getErrorStream());
 
         // Halt the current thread until the process is complete, if the exit code isn't 0, throw an exception
-        int exitCode;
-        if ((exitCode = p.waitFor()) != 0) {
+        int exitCode = p.waitFor();
+        if (exitCode != 0) {
             throw new Exception("Proguard exited with code " + exitCode);
         }
     }
diff --git a/buildSrc/src/main/java/baritone/gradle/util/Determinizer.java b/buildSrc/src/main/java/baritone/gradle/util/Determinizer.java
index f08649d2..d50c1e54 100644
--- a/buildSrc/src/main/java/baritone/gradle/util/Determinizer.java
+++ b/buildSrc/src/main/java/baritone/gradle/util/Determinizer.java
@@ -39,39 +39,39 @@ import java.util.stream.Collectors;
  */
 public class Determinizer {
 
-    public static void main(String... args) throws IOException {
+    public static void determinize(String inputPath, String outputPath) throws IOException {
         System.out.println("Running Determinizer");
-        System.out.println(" Input path: " + args[0]);
-        System.out.println(" Output path: " + args[1]);
+        System.out.println(" Input path: " + inputPath);
+        System.out.println(" Output path: " + outputPath);
 
-        JarFile jarFile = new JarFile(new File(args[0]));
-        JarOutputStream jos = new JarOutputStream(new FileOutputStream(new File(args[1])));
+        try (
+                JarFile jarFile = new JarFile(new File(inputPath));
+                JarOutputStream jos = new JarOutputStream(new FileOutputStream(new File(outputPath)))
+        ) {
 
-        List<JarEntry> entries = jarFile.stream()
-                .sorted(Comparator.comparing(JarEntry::getName))
-                .collect(Collectors.toList());
+            List<JarEntry> entries = jarFile.stream()
+                    .sorted(Comparator.comparing(JarEntry::getName))
+                    .collect(Collectors.toList());
 
-        for (JarEntry entry : entries) {
-            if (entry.getName().equals("META-INF/fml_cache_annotation.json")) {
-                continue;
-            }
-            if (entry.getName().equals("META-INF/fml_cache_class_versions.json")) {
-                continue;
-            }
-            JarEntry clone = new JarEntry(entry.getName());
-            clone.setTime(42069);
-            jos.putNextEntry(clone);
-            if (entry.getName().endsWith(".refmap.json")) {
-                JsonObject object = new JsonParser().parse(new InputStreamReader(jarFile.getInputStream(entry))).getAsJsonObject();
-                copy(writeSorted(object), jos);
-            } else {
-                copy(jarFile.getInputStream(entry), jos);
+            for (JarEntry entry : entries) {
+                if (entry.getName().equals("META-INF/fml_cache_annotation.json")) {
+                    continue;
+                }
+                if (entry.getName().equals("META-INF/fml_cache_class_versions.json")) {
+                    continue;
+                }
+                JarEntry clone = new JarEntry(entry.getName());
+                clone.setTime(42069);
+                jos.putNextEntry(clone);
+                if (entry.getName().endsWith(".refmap.json")) {
+                    JsonObject object = new JsonParser().parse(new InputStreamReader(jarFile.getInputStream(entry))).getAsJsonObject();
+                    jos.write(writeSorted(object).getBytes());
+                } else {
+                    copy(jarFile.getInputStream(entry), jos);
+                }
             }
+            jos.finish();
         }
-
-        jos.finish();
-        jos.close();
-        jarFile.close();
     }
 
     private static void copy(InputStream is, OutputStream os) throws IOException {
@@ -82,10 +82,6 @@ public class Determinizer {
         }
     }
 
-    private static void copy(String s, OutputStream os) throws IOException {
-        os.write(s.getBytes());
-    }
-
     private static String writeSorted(JsonObject in) throws IOException {
         StringWriter writer = new StringWriter();
         JsonWriter jw = new JsonWriter(writer);