diff --git a/src/main/java/detrav/net/DetravNetwork.java b/src/main/java/detrav/net/DetravNetwork.java
index 30bdb23157e..be3a440456c 100644
--- a/src/main/java/detrav/net/DetravNetwork.java
+++ b/src/main/java/detrav/net/DetravNetwork.java
@@ -38,9 +38,10 @@ protected void encode(ChannelHandlerContext ctx, DetravPacket msg, List<Object>
         ByteBuf buf = Unpooled.buffer();
         buf.writeByte(msg.getPacketID());
         msg.encode(new ByteBufOutputStream(buf));
+        // FMLProxyPacket sends the whole backing array of its buffer, so give it one holding only the written bytes
         out.add(
             new FMLProxyPacket(
-                buf,
+                buf.copy(),
                 ctx.channel()
                     .attr(NetworkRegistry.FML_CHANNEL)
                     .get()));
diff --git a/src/main/java/gregtech/api/net/GTPacketLMACraftingFX.java b/src/main/java/gregtech/api/net/GTPacketLMACraftingFX.java
index 35537e75066..5f2a7eeaa9c 100644
--- a/src/main/java/gregtech/api/net/GTPacketLMACraftingFX.java
+++ b/src/main/java/gregtech/api/net/GTPacketLMACraftingFX.java
@@ -51,7 +51,9 @@ public void encode(ByteBuf buffer) {
         try {
             ByteBuf stackBuffer = Unpooled.buffer();
             itemStack.writeToPacket(stackBuffer);
-            byte[] data = stackBuffer.array();
+            // only the written bytes: the backing array also holds the buffer's unused capacity
+            byte[] data = new byte[stackBuffer.readableBytes()];
+            stackBuffer.readBytes(data);
             buffer.writeInt(data.length);
             buffer.writeBytes(data);
         } catch (IOException e) {
diff --git a/src/main/java/gregtech/common/GTNetwork.java b/src/main/java/gregtech/common/GTNetwork.java
index f118f7120e0..892f498669f 100644
--- a/src/main/java/gregtech/common/GTNetwork.java
+++ b/src/main/java/gregtech/common/GTNetwork.java
@@ -55,9 +55,10 @@ protected void encode(ChannelHandlerContext aContext, GTPacket aPacket, List<Obj
         final ByteBuf tBuf = Unpooled.buffer()
             .writeByte(aPacket.getPacketID());
         aPacket.encode(tBuf);
+        // FMLProxyPacket sends the whole backing array of its buffer, so give it one holding only the written bytes
         aOutput.add(
             new FMLProxyPacket(
-                tBuf,
+                tBuf.copy(),
                 aContext.channel()
                     .attr(NetworkRegistry.FML_CHANNEL)
                     .get()));