diff --git a/core/c/build.gradle b/core/c/build.gradle
index ccceef1c..baabdcd4 100644
--- a/core/c/build.gradle
+++ b/core/c/build.gradle
@@ -29,7 +29,7 @@ library {
             //TODO: Cross-compiling, blocked by: https://github.com/gradle/gradle-native/issues/169
             //setTargets( "arm", "arm64", "x86-64", "x86" )
             eachPlatform {
-                cppCompiler.withArguments { addAll( ["-x", "c", "-std=c11", "-DMPW_SODIUM=1"] ) }
+                cppCompiler.withArguments { addAll( ["-x", "c", "-std=c11", "-Werror", "-DMPW_SODIUM=1"] ) }
             }
         }
     }
diff --git a/core/c/src/mpw-jni.c b/core/c/src/mpw-jni.c
index e40a6b9d..efcfc3d7 100644
--- a/core/c/src/mpw-jni.c
+++ b/core/c/src/mpw-jni.c
@@ -3,13 +3,16 @@
 #include "mpw-jni.h"
 #include "mpw-util.h"
 
-/** native int _scrypt(byte[] passwd, int passwdlen, byte[] salt, int saltlen, int N, int r, int p, byte[] buf, int buflen); */
+/** native int _scrypt(byte[] passwd, byte[] salt, int N, int r, int p, byte[] buf); */
 JNIEXPORT jint JNICALL Java_com_lyndir_masterpassword_impl_MPAlgorithmV0__1scrypt(JNIEnv *env, jobject obj,
-        jbyteArray passwd, jint passwdlen, jbyteArray salt, jint saltlen, jint N, jint r, jint p, jbyteArray buf, jint buflen) {
+        jbyteArray passwd, jbyteArray salt, jint N, jint r, jint p, jbyteArray buf) {
 
     jbyte *passwdBytes = (*env)->GetByteArrayElements( env, passwd, NULL );
     jbyte *saltBytes = (*env)->GetByteArrayElements( env, salt, NULL );
-    const uint8_t *key = mpw_kdf_scrypt( (size_t)buflen, (uint8_t *)passwdBytes, (size_t)passwdlen, (uint8_t *)saltBytes, (size_t)saltlen,
+    const size_t keyLength = (*env)->GetArrayLength( env, buf );
+    const uint8_t *key = mpw_kdf_scrypt( keyLength,
+            (uint8_t *)passwdBytes, (size_t)(*env)->GetArrayLength( env, passwd ),
+            (uint8_t *)saltBytes, (size_t)(*env)->GetArrayLength( env, salt ),
             (uint64_t)N, (uint32_t)r, (uint32_t)p );
     (*env)->ReleaseByteArrayElements( env, passwd, passwdBytes, JNI_ABORT );
     (*env)->ReleaseByteArrayElements( env, salt, saltBytes, JNI_ABORT );
@@ -17,6 +20,10 @@ JNIEXPORT jint JNICALL Java_com_lyndir_masterpassword_impl_MPAlgorithmV0__1scryp
     if (!key)
         return ERR;
 
-    memcpy( buf, key, buflen );
+    jbyte *bufBytes = (*env)->GetByteArrayElements( env, buf, NULL );
+    memcpy( bufBytes, key, keyLength );
+    (*env)->ReleaseByteArrayElements( env, buf, bufBytes, JNI_OK );
+    mpw_free( &key, keyLength );
+
     return OK;
 }
diff --git a/core/c/src/mpw-jni.h b/core/c/src/mpw-jni.h
index 09756303..e9116a74 100644
--- a/core/c/src/mpw-jni.h
+++ b/core/c/src/mpw-jni.h
@@ -1,5 +1,4 @@
 /* DO NOT EDIT THIS FILE - it is machine generated */
-#undef __cplusplus
 #include <jni.h>
 /* Header for class com_lyndir_masterpassword_impl_MPAlgorithmV0 */
 
@@ -13,10 +12,10 @@ extern "C" {
 /*
  * Class:     com_lyndir_masterpassword_impl_MPAlgorithmV0
  * Method:    _scrypt
- * Signature: ([BI[BIIII[BI)I
+ * Signature: ([B[BIII[B)I
  */
 JNIEXPORT jint JNICALL Java_com_lyndir_masterpassword_impl_MPAlgorithmV0__1scrypt
-  (JNIEnv *, jobject, jbyteArray, jint, jbyteArray, jint, jint, jint, jint, jbyteArray, jint);
+  (JNIEnv *, jobject, jbyteArray, jbyteArray, jint, jint, jint, jbyteArray);
 
 #ifdef __cplusplus
 }
diff --git a/core/java/algorithm/build.gradle b/core/java/algorithm/build.gradle
index 0b446c73..b50b2833 100644
--- a/core/java/algorithm/build.gradle
+++ b/core/java/algorithm/build.gradle
@@ -28,3 +28,11 @@ processResources {
         }
     } )
 }
+
+compileJava {
+    doLast {
+        ant.javah( class: 'com.lyndir.masterpassword.impl.MPAlgorithmV0',
+                   outputFile: '../../c/src/mpw-jni.h',
+                   classpath: files( sourceSets.main.compileClasspath, sourceSets.main.output ).asPath )
+    }
+}
diff --git a/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV0.java b/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV0.java
index 3a5a3a1b..cef8080a 100644
--- a/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV0.java
+++ b/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV0.java
@@ -90,15 +90,13 @@ public class MPAlgorithmV0 extends MPAlgorithm {
     @Nullable
     protected byte[] scrypt(final byte[] secret, final byte[] salt, final int keySize) {
         byte[] buffer = new byte[keySize];
-        if (_scrypt(
-                secret, secret.length, salt, salt.length,
-                scrypt_N(), scrypt_r(), scrypt_p(), buffer, buffer.length ) < 0)
+        if (_scrypt( secret, salt, scrypt_N(), scrypt_r(), scrypt_p(), buffer ) < 0)
             return null;
 
         return buffer;
     }
 
-    protected native int _scrypt(byte[] passwd, int passwdlen, byte[] salt, int saltlen, int N, int r, int p, byte[] buf, int buflen);
+    protected native int _scrypt(byte[] passwd, byte[] salt, int N, int r, int p, byte[] buf);
 
     @Override
     public byte[] siteKey(final byte[] masterKey, final String siteName, UnsignedInteger siteCounter,
diff --git a/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV3.java b/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV3.java
index e98db097..e6013216 100644
--- a/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV3.java
+++ b/core/java/algorithm/src/main/java/com/lyndir/masterpassword/impl/MPAlgorithmV3.java
@@ -50,7 +50,7 @@ public class MPAlgorithmV3 extends MPAlgorithmV2 {
         logger.trc( "masterKey: scrypt( masterPassword, masterKeySalt, N=%d, r=%d, p=%d )",
                     scrypt_N(), scrypt_r(), scrypt_p() );
         byte[] masterPasswordBytes = toBytes( masterPassword );
-        byte[] masterKey           = scrypt( masterKeySalt, masterPasswordBytes, mpw_dkLen() );
+        byte[] masterKey           = scrypt( masterPasswordBytes, masterKeySalt, mpw_dkLen() );
         Arrays.fill( masterKeySalt, (byte) 0 );
         Arrays.fill( masterPasswordBytes, (byte) 0 );
         if (masterKey == null)
diff --git a/core/java/tests/src/main/java/com/lyndir/masterpassword/MPTests.java b/core/java/tests/src/main/java/com/lyndir/masterpassword/MPTests.java
index 67573c2f..c486dfb6 100644
--- a/core/java/tests/src/main/java/com/lyndir/masterpassword/MPTests.java
+++ b/core/java/tests/src/main/java/com/lyndir/masterpassword/MPTests.java
@@ -60,7 +60,7 @@ public class MPTests {
     }
 
     public Case getCase(final String identifier) {
-        for (final Case testCase : getCases())
+        for (final Case testCase : cases)
             if (identifier.equals( testCase.getIdentifier() ))
                 return testCase;
 
diff --git a/core/java/tests/src/test/java/com/lyndir/masterpassword/MPMasterKeyTest.java b/core/java/tests/src/test/java/com/lyndir/masterpassword/MPMasterKeyTest.java
index 939e2f7e..181e459c 100644
--- a/core/java/tests/src/test/java/com/lyndir/masterpassword/MPMasterKeyTest.java
+++ b/core/java/tests/src/test/java/com/lyndir/masterpassword/MPMasterKeyTest.java
@@ -39,7 +39,7 @@ public class MPMasterKeyTest {
             throws Exception {
 
         testSuite = new MPTestSuite();
-        //testSuite.getTests().addFilters( "v0" );
+        //testSuite.getTests().addFilters( "v3_type_maximum" );
     }
 
     @Test