diff --git a/src/main/java/dan200/computercraft/core/apis/HTTPAPI.java b/src/main/java/dan200/computercraft/core/apis/HTTPAPI.java
index 2f531723f..768afd017 100644
--- a/src/main/java/dan200/computercraft/core/apis/HTTPAPI.java
+++ b/src/main/java/dan200/computercraft/core/apis/HTTPAPI.java
@@ -17,8 +17,8 @@ import java.util.*;
 
 public class HTTPAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_apiEnvironment;
-    private List<HTTPRequest> m_httpRequests;
+    private final IAPIEnvironment m_apiEnvironment;
+    private final List<HTTPRequest> m_httpRequests;
     
     public HTTPAPI( IAPIEnvironment environment )
     {
diff --git a/src/main/java/dan200/computercraft/core/apis/HTTPRequest.java b/src/main/java/dan200/computercraft/core/apis/HTTPRequest.java
index 55390c262..b7f816ad7 100644
--- a/src/main/java/dan200/computercraft/core/apis/HTTPRequest.java
+++ b/src/main/java/dan200/computercraft/core/apis/HTTPRequest.java
@@ -278,8 +278,8 @@ public class HTTPRequest
         return null;
     }
     
-    private Object m_lock = new Object();
-    private URL m_url;
+    private final Object m_lock = new Object();
+    private final URL m_url;
     private final String m_urlString;
     
     private boolean m_complete;
diff --git a/src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java b/src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java
index 01edb43a6..64a39c801 100644
--- a/src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java
+++ b/src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java
@@ -235,9 +235,9 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         }
     }
     
-    private IAPIEnvironment m_environment;
+    private final IAPIEnvironment m_environment;
     private FileSystem m_fileSystem;
-    private PeripheralWrapper[] m_peripherals;
+    private final PeripheralWrapper[] m_peripherals;
     private boolean m_running;
 
     public PeripheralAPI( IAPIEnvironment _environment )
diff --git a/src/main/java/dan200/computercraft/core/apis/TermAPI.java b/src/main/java/dan200/computercraft/core/apis/TermAPI.java
index 926cc51b9..dfaf3afd0 100644
--- a/src/main/java/dan200/computercraft/core/apis/TermAPI.java
+++ b/src/main/java/dan200/computercraft/core/apis/TermAPI.java
@@ -15,8 +15,8 @@ import javax.annotation.Nonnull;
 
 public class TermAPI implements ILuaAPI
 {
-    private Terminal m_terminal;
-    private IComputerEnvironment m_environment;
+    private final Terminal m_terminal;
+    private final IComputerEnvironment m_environment;
 
     public TermAPI( IAPIEnvironment _environment )
     {
diff --git a/src/main/java/dan200/computercraft/core/computer/Computer.java b/src/main/java/dan200/computercraft/core/computer/Computer.java
index 51c38eb29..460982ff1 100644
--- a/src/main/java/dan200/computercraft/core/computer/Computer.java
+++ b/src/main/java/dan200/computercraft/core/computer/Computer.java
@@ -186,26 +186,26 @@ public class Computer
     private boolean m_blinking;
 
     private ILuaMachine m_machine;
-    private List<ILuaAPI> m_apis;
-    private APIEnvironment m_apiEnvironment;
+    private final List<ILuaAPI> m_apis;
+    private final APIEnvironment m_apiEnvironment;
     
-    private Terminal m_terminal;
+    private final Terminal m_terminal;
     private FileSystem m_fileSystem;
     private IWritableMount m_rootMount;
 
-    private int[] m_internalOutput;
-    private int[] m_internalBundledOutput;
+    private final int[] m_internalOutput;
+    private final int[] m_internalBundledOutput;
     private boolean m_internalOutputChanged;
 
-    private int[] m_externalOutput;
-    private int[] m_externalBundledOutput;
+    private final int[] m_externalOutput;
+    private final int[] m_externalBundledOutput;
     private boolean m_externalOutputChanged;
 
-    private int[] m_input;
-    private int[] m_bundledInput;
+    private final int[] m_input;
+    private final int[] m_bundledInput;
     private boolean m_inputChanged;
         
-    private IPeripheral[] m_peripherals;
+    private final IPeripheral[] m_peripherals;
 
     public Computer( IComputerEnvironment environment, Terminal terminal, int id )
     {
diff --git a/src/main/java/dan200/computercraft/core/computer/ComputerThread.java b/src/main/java/dan200/computercraft/core/computer/ComputerThread.java
index 98297fe23..49d739c95 100644
--- a/src/main/java/dan200/computercraft/core/computer/ComputerThread.java
+++ b/src/main/java/dan200/computercraft/core/computer/ComputerThread.java
@@ -13,14 +13,14 @@ import java.util.concurrent.LinkedBlockingQueue;
     
 public class ComputerThread
 {
-    private static Object m_lock;
+    private static final Object m_lock;
     
     private static Thread m_thread;
-    private static WeakHashMap <Object, LinkedBlockingQueue<ITask>> m_computerTasks;
-    private static ArrayList <LinkedBlockingQueue<ITask>> m_computerTasksActive;
-    private static ArrayList <LinkedBlockingQueue<ITask>> m_computerTasksPending;
-    private static Object m_defaultQueue;
-    private static Object m_monitor;
+    private static final WeakHashMap <Object, LinkedBlockingQueue<ITask>> m_computerTasks;
+    private static final ArrayList <LinkedBlockingQueue<ITask>> m_computerTasksActive;
+    private static final ArrayList <LinkedBlockingQueue<ITask>> m_computerTasksPending;
+    private static final Object m_defaultQueue;
+    private static final Object m_monitor;
 
     private static boolean m_running;
     private static boolean m_stopped;
diff --git a/src/main/java/dan200/computercraft/shared/peripheral/modem/ModemPeripheral.java b/src/main/java/dan200/computercraft/shared/peripheral/modem/ModemPeripheral.java
index b26a59440..f3033e5f8 100644
--- a/src/main/java/dan200/computercraft/shared/peripheral/modem/ModemPeripheral.java
+++ b/src/main/java/dan200/computercraft/shared/peripheral/modem/ModemPeripheral.java
@@ -84,7 +84,7 @@ public abstract class ModemPeripheral
     
     private INetwork m_network;
     private IComputerAccess m_computer;
-    private Map<Integer, IReceiver> m_channels;
+    private final Map<Integer, IReceiver> m_channels;
 
     private boolean m_open;
     private boolean m_changed;
diff --git a/src/main/java/dan200/computercraft/shared/peripheral/modem/TileCable.java b/src/main/java/dan200/computercraft/shared/peripheral/modem/TileCable.java
index c1dcd71f4..8eb6669e3 100644
--- a/src/main/java/dan200/computercraft/shared/peripheral/modem/TileCable.java
+++ b/src/main/java/dan200/computercraft/shared/peripheral/modem/TileCable.java
@@ -233,13 +233,13 @@ public class TileCable extends TileModemBase
 
     // Members
 
-    private Map<Integer, Set<IReceiver>> m_receivers;
-    private Queue<Packet> m_transmitQueue;
+    private final Map<Integer, Set<IReceiver>> m_receivers;
+    private final Queue<Packet> m_transmitQueue;
     
     private boolean m_peripheralAccessAllowed;
     private int m_attachedPeripheralID;
     
-    private Map<String, IPeripheral> m_peripheralsByName;
+    private final Map<String, IPeripheral> m_peripheralsByName;
     private Map<String, RemotePeripheralWrapper> m_peripheralWrappersByName;
     private boolean m_peripheralsKnown;
     private boolean m_destroyed;
diff --git a/src/main/java/dan200/computercraft/shared/peripheral/printer/TilePrinter.java b/src/main/java/dan200/computercraft/shared/peripheral/printer/TilePrinter.java
index 78ad00e5a..f54d07425 100644
--- a/src/main/java/dan200/computercraft/shared/peripheral/printer/TilePrinter.java
+++ b/src/main/java/dan200/computercraft/shared/peripheral/printer/TilePrinter.java
@@ -447,16 +447,8 @@ public class TilePrinter extends TilePeripheralBase
     {
         synchronized( m_inventory )
         {
-            ItemStack inkStack = m_inventory[0];
-            if( inkStack == null || !isInk(inkStack) )
-            {
-                return false;
-            }
-            if( getPaperLevel() > 0 )
-            {
-                return true;
-            }
-            return false;
+            ItemStack inkStack = m_inventory[ 0 ];
+            return inkStack != null && isInk( inkStack ) && getPaperLevel() > 0;
         }
     }
     
diff --git a/src/main/java/dan200/computercraft/shared/pocket/peripherals/PocketModemPeripheral.java b/src/main/java/dan200/computercraft/shared/pocket/peripherals/PocketModemPeripheral.java
index de8b2669e..69f100edc 100644
--- a/src/main/java/dan200/computercraft/shared/pocket/peripherals/PocketModemPeripheral.java
+++ b/src/main/java/dan200/computercraft/shared/pocket/peripherals/PocketModemPeripheral.java
@@ -52,10 +52,6 @@ public class PocketModemPeripheral extends WirelessModemPeripheral
     @Override
     public boolean equals( IPeripheral other )
     {
-        if( other instanceof PocketModemPeripheral )
-        {
-            return true;
-        }
-        return false;
+        return other instanceof PocketModemPeripheral;
     }
 }
diff --git a/src/main/java/dan200/computercraft/shared/proxy/CCTurtleProxyCommon.java b/src/main/java/dan200/computercraft/shared/proxy/CCTurtleProxyCommon.java
index 86dd2adb5..1702855f9 100644
--- a/src/main/java/dan200/computercraft/shared/proxy/CCTurtleProxyCommon.java
+++ b/src/main/java/dan200/computercraft/shared/proxy/CCTurtleProxyCommon.java
@@ -112,7 +112,6 @@ public abstract class CCTurtleProxyCommon implements ICCTurtleProxy
             }
             catch( Exception e )
             {
-                continue;
             }
         }
         return null;
diff --git a/src/main/java/dan200/computercraft/shared/turtle/blocks/TileTurtle.java b/src/main/java/dan200/computercraft/shared/turtle/blocks/TileTurtle.java
index edbc78a2b..09c80c0b9 100644
--- a/src/main/java/dan200/computercraft/shared/turtle/blocks/TileTurtle.java
+++ b/src/main/java/dan200/computercraft/shared/turtle/blocks/TileTurtle.java
@@ -245,11 +245,7 @@ public class TileTurtle extends TileComputerBase
         }
         else
         {
-            if( exploder != null && ( exploder instanceof EntityLivingBase || exploder instanceof EntityFireball ) )
-            {
-                return true;
-            }
-            return false;
+            return exploder != null && (exploder instanceof EntityLivingBase || exploder instanceof EntityFireball);
         }
     }
 
@@ -705,11 +701,7 @@ public class TileTurtle extends TileComputerBase
             case 5:    upgrade = getUpgrade( TurtleSide.Left ); break;
             default: return false;
         }
-        if( upgrade != null && upgrade.getType().isPeripheral() )
-        {
-            return true;
-        }
-        return false;
+        return upgrade != null && upgrade.getType().isPeripheral();
     }
 
     public void transferStateFrom( TileTurtle copy )
diff --git a/src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java b/src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java
index 48ce2d373..787a8532a 100644
--- a/src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java
+++ b/src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java
@@ -140,11 +140,7 @@ public class TurtleTool implements ITurtleUpgrade
     {
         IBlockState state = world.getBlockState( pos );
         Block block = state.getBlock();
-        if( block.isAir( state, world, pos ) || block == Blocks.BEDROCK || state.getBlockHardness( world, pos ) <= -1.0F )
-        {
-            return false;
-        }
-        return true;
+        return !block.isAir( state, world, pos ) && block != Blocks.BEDROCK && state.getBlockHardness( world, pos ) > -1.0F;
     }
     
     protected boolean canHarvestBlock( World world, BlockPos pos )
diff --git a/src/main/java/dan200/computercraft/shared/util/IDAssigner.java b/src/main/java/dan200/computercraft/shared/util/IDAssigner.java
index d6eda9687..b1eb6910e 100644
--- a/src/main/java/dan200/computercraft/shared/util/IDAssigner.java
+++ b/src/main/java/dan200/computercraft/shared/util/IDAssigner.java
@@ -50,7 +50,6 @@ public class IDAssigner
                     }
                     catch( NumberFormatException e )
                     {
-                        continue;
                     }
                 }
             }