diff --git a/build.gradle b/build.gradle
index 1395e429..5b298ac6 100755
--- a/build.gradle
+++ b/build.gradle
@@ -22,7 +22,7 @@ apply plugin: 'forge' // adds the forge dependency
 apply plugin: 'maven' // for uploading to a maven repo
 apply plugin: 'checkstyle'
 
-version = "7.1.20"
+version = "7.1.21"
 group= "com.mod-buildcraft"
 archivesBaseName = "buildcraft" // the name that all artifacts will use as a base. artifacts names follow this pattern: [baseName]-[appendix]-[version]-[classifier].[extension]
 
diff --git a/buildcraft_resources/changelog/7.1.21 b/buildcraft_resources/changelog/7.1.21
new file mode 100644
index 00000000..b99736b6
--- /dev/null
+++ b/buildcraft_resources/changelog/7.1.21
@@ -0,0 +1,7 @@
+Bugs fixed:
+
+* [#3503] Auto Workbench dupe bug (asie)
+* [#3500] Rare division by zero error on world load (asie)
+* [#3498] Refinery deletes insufficient input fluids for non-standard refinery recipes (asie)
+* [#3496] Crafting Table IV rendering crash (asie)
+* [#3307] Auto Workbench not reacting to item insertion correctly in all cases (asie)
\ No newline at end of file
diff --git a/buildcraft_resources/versions.txt b/buildcraft_resources/versions.txt
index b3e1c807..53ffac8b 100755
--- a/buildcraft_resources/versions.txt
+++ b/buildcraft_resources/versions.txt
@@ -1,3 +1,3 @@
 1.6.4:BuildCraft:4.2.2
 1.7.2:BuildCraft:6.0.16
-1.7.10:BuildCraft:7.1.20
+1.7.10:BuildCraft:7.1.21
diff --git a/common/buildcraft/BuildCraftCore.java b/common/buildcraft/BuildCraftCore.java
index 7b3377e8..fd90a2d7 100644
--- a/common/buildcraft/BuildCraftCore.java
+++ b/common/buildcraft/BuildCraftCore.java
@@ -646,8 +646,9 @@ public class BuildCraftCore extends BuildCraftMod {
 
 			BuildingSlotMapIterator.MAX_PER_ITEM = builderMaxPerItemFactor;
 
-			if (miningMultiplier <= 0)
+			if (miningMultiplier <= 0) {
 				throw new RuntimeException("Please do not set the miningMultiplier to values <= 0.0!");
+			}
 
 			if (mainConfigManager.get("general.updateCheck").getBoolean(true)) {
 				Version.check();
diff --git a/common/buildcraft/core/lib/utils/FluidUtils.java b/common/buildcraft/core/lib/utils/FluidUtils.java
index 4b276501..44005936 100644
--- a/common/buildcraft/core/lib/utils/FluidUtils.java
+++ b/common/buildcraft/core/lib/utils/FluidUtils.java
@@ -1,7 +1,6 @@
 package buildcraft.core.lib.utils;
 
 import net.minecraft.block.Block;
-import net.minecraft.init.Blocks;
 import net.minecraft.item.ItemBlock;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.fluids.Fluid;
diff --git a/common/buildcraft/energy/worldgen/OilPopulate.java b/common/buildcraft/energy/worldgen/OilPopulate.java
index 3a685f6f..a092be99 100644
--- a/common/buildcraft/energy/worldgen/OilPopulate.java
+++ b/common/buildcraft/energy/worldgen/OilPopulate.java
@@ -12,7 +12,6 @@ import java.util.HashSet;
 import java.util.Random;
 import java.util.Set;
 
-import buildcraft.core.lib.block.BlockBuildCraftFluid;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockFlower;
 import net.minecraft.block.BlockStaticLiquid;
@@ -34,6 +33,7 @@ import net.minecraftforge.fluids.IFluidBlock;
 
 import buildcraft.BuildCraftCore;
 import buildcraft.BuildCraftEnergy;
+import buildcraft.core.lib.block.BlockBuildCraftFluid;
 
 public final class OilPopulate {
 
diff --git a/common/buildcraft/factory/TileAutoWorkbench.java b/common/buildcraft/factory/TileAutoWorkbench.java
index 464d6486..cb488e55 100644
--- a/common/buildcraft/factory/TileAutoWorkbench.java
+++ b/common/buildcraft/factory/TileAutoWorkbench.java
@@ -11,7 +11,6 @@ package buildcraft.factory;
 import java.lang.ref.WeakReference;
 import java.util.List;
 
-import buildcraft.api.tiles.IDebuggable;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.IInventory;
 import net.minecraft.inventory.ISidedInventory;
@@ -29,6 +28,7 @@ import net.minecraftforge.common.util.ForgeDirection;
 import buildcraft.api.core.IInvSlot;
 import buildcraft.api.power.IRedstoneEngine;
 import buildcraft.api.power.IRedstoneEngineReceiver;
+import buildcraft.api.tiles.IDebuggable;
 import buildcraft.api.tiles.IHasWork;
 import buildcraft.core.lib.RFBattery;
 import buildcraft.core.lib.block.TileBuildCraft;