diff --git a/platform-independent/c/core/Dockerfile.x86 b/platform-independent/c/core/Dockerfile.x86
new file mode 100644
index 00000000..c07c9c30
--- /dev/null
+++ b/platform-independent/c/core/Dockerfile.x86
@@ -0,0 +1,9 @@
+FROM i386/debian:stable-slim
+ENTRYPOINT ["linux32", "--"]
+
+# https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199
+RUN mkdir -p /usr/share/man/man1
+
+RUN apt-get update && apt-get install -y default-jdk-headless git-core bash libtool automake autoconf make g++
+RUN git clone --depth=3 $(: --shallow-submodules) --recurse-submodules --branch rewrite https://gitlab.com/MasterPassword/MasterPassword.git /mpw
+RUN cd /mpw && git log -1 && ./gradlew -i clean build
diff --git a/Dockerfile b/platform-independent/c/core/Dockerfile.x86_64
similarity index 61%
rename from Dockerfile
rename to platform-independent/c/core/Dockerfile.x86_64
index 89bb6a0c..31ec5f6e 100644
--- a/Dockerfile
+++ b/platform-independent/c/core/Dockerfile.x86_64
@@ -1,12 +1,8 @@
 FROM debian:stable-slim
 
-# For i386
-#FROM i386/debian:stable-slim
-#ENTRYPOINT ["linux32", "--"]
-
 # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199
 RUN mkdir -p /usr/share/man/man1
 
 RUN apt-get update && apt-get install -y default-jdk-headless git-core bash libtool automake autoconf make g++
-RUN git clone --depth=3 $(: --shallow-submodules) --recurse-submodules https://gitlab.com/MasterPassword/MasterPassword.git /mpw
-RUN cd /mpw/gradle && ./gradlew -i clean build
+RUN git clone --depth=3 $(: --shallow-submodules) --recurse-submodules --branch rewrite https://gitlab.com/MasterPassword/MasterPassword.git /mpw
+RUN cd /mpw && git log -1 && ./gradlew -i clean build
diff --git a/platform-independent/c/core/build.gradle b/platform-independent/c/core/build.gradle
index 99dc6ed5..4dd47136 100644
--- a/platform-independent/c/core/build.gradle
+++ b/platform-independent/c/core/build.gradle
@@ -25,37 +25,36 @@ artifacts {
 library {
     baseName.set( 'mpw' )
     linkage.set( [Linkage.SHARED] )
-    source.from fileTree( 'src' )
+    source.from files( 'src' )
 
-    // Reconfigure the toolchain from C++ to C.
-    toolChains {
-        withType( VisualCpp ) {
-            eachPlatform {
-                cppCompiler.withArguments { addAll( ['/TC', '/MT', '/Ox', '/DMPW_SODIUM=1', '/DSODIUM_STATIC', '/DSODIUM_EXPORT=', '/DMPW_LOG=mpw_log_app'] ) }
-            }
-        }
-        withType( GccCompatibleToolChain ) {
-            eachPlatform {
-                cppCompiler.withArguments { addAll( ['-x', 'c', '-O3', '-Werror', '-DMPW_SODIUM=1', '-DMPW_LOG=mpw_log_app'] ) }
-            }
-        }
-    }
+    // JDK for JNI support.
+    privateHeaders.from files( new File( Jvm.current().javaHome, 'include' ) ) { first().eachDir { from it } }
 
-    // Cross-compile for these host platforms.
-    // TODO: Cross-compiling, blocked by: https://github.com/gradle/gradle-native/issues/169 - CppLibraryPlugin.java:163
-//    operatingSystems.set( [objects.named( OperatingSystemFamily, OperatingSystemFamily.LINUX ),
-//                           objects.named( OperatingSystemFamily, OperatingSystemFamily.MAC_OS ),
-//                           objects.named( OperatingSystemFamily, OperatingSystemFamily.WINDOWS )] )
+    // Cross-compile for these target platforms.
+    // TODO: Cross-compiling, blocked by: https://github.com/gradle/gradle-native/issues/1031
     targetMachines.set( [
-            machines.linux.x86_64,
+            machines.linux.x86, machines.linux.x86_64,
             machines.windows.x86, machines.windows.x86_64,
             machines.macOS.x86_64
     ] )
 
-    components.withType( CppComponent ) {
-        // JDK for JNI support.
-        privateHeaders.from files( new File( Jvm.current().javaHome, 'include' ) ) { first().eachDir { from it } }
+    tasks.withType(CppCompile).configureEach {
+        // Define a preprocessor macro for every binary
+        macros.put("MPW_SODIUM", "1")
+        macros.put("MPW_LOG", "mpw_log_app")
 
+        // Reconfigure the toolchain from C++ to C.
+        compilerArgs.addAll toolChain.map { toolChain ->
+            if (toolChain in GccCompatibleToolChain) {
+                return ['-x', 'c', '-O3', '-Werror']
+            } else if (toolChain in VisualCpp) {
+                return ['/TC', '/MT', '/Ox', '/DSODIUM_STATIC', '/DSODIUM_EXPORT=']
+            }
+            return []
+        }
+    }
+
+    components.withType( CppComponent ) {
         binaries.whenElementFinalized {
             project.dependencies {
                 def system = targetMachine.getOperatingSystemFamily().getName()
diff --git a/platform-independent/c/core/src/mpw-jni.c b/platform-independent/c/core/src/mpw-jni.c
index 0f9e28e6..f3a6798d 100644
--- a/platform-independent/c/core/src/mpw-jni.c
+++ b/platform-independent/c/core/src/mpw-jni.c
@@ -29,10 +29,11 @@ void mpw_log_app(LogLevel level, const char *format, ...) {
         else if (level <= LogLevelError)
             method = (*env)->GetMethodID( env, class, "error", "(Ljava/lang/String;)V" );
 
-        char *message = NULL;
-        int length = vasprintf( &message, format, args );
-        if (message) {
-            (*env)->CallVoidMethod( env, logger, method, (*env)->NewStringUTF( env, message ) );
+        int length = vsnprintf( NULL, 0, format, args );
+        if (length > 0) {
+            char *message = malloc( length + 1 );
+            if (message && (length = vsnprintf( message, length, format, args )) > 0);
+                (*env)->CallVoidMethod( env, logger, method, (*env)->NewStringUTF( env, message ) );
             mpw_free( &message, (size_t)max( 0, length ) );
         }