diff --git a/buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts b/buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts
index 8bd8d0f77..b216d4003 100644
--- a/buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts
+++ b/buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts
@@ -80,7 +80,7 @@ sourceSets.all {
             check("FutureReturnValueIgnored", CheckSeverity.OFF) // Too many false positives with Netty
 
             check("NullAway", CheckSeverity.ERROR)
-            option("NullAway:AnnotatedPackages", listOf("dan200.computercraft").joinToString(","))
+            option("NullAway:AnnotatedPackages", listOf("dan200.computercraft", "net.fabricmc.fabric.api").joinToString(","))
             option("NullAway:ExcludedFieldAnnotations", listOf("org.spongepowered.asm.mixin.Shadow").joinToString(","))
             option("NullAway:CastToNonNullMethod", "dan200.computercraft.core.util.Nullability.assertNonNull")
             option("NullAway:CheckOptionalEmptiness")
diff --git a/projects/common/src/testMod/kotlin/dan200/computercraft/gametest/Turtle_Test.kt b/projects/common/src/testMod/kotlin/dan200/computercraft/gametest/Turtle_Test.kt
index 7fff8c493..7ebe00394 100644
--- a/projects/common/src/testMod/kotlin/dan200/computercraft/gametest/Turtle_Test.kt
+++ b/projects/common/src/testMod/kotlin/dan200/computercraft/gametest/Turtle_Test.kt
@@ -289,6 +289,23 @@ fun Refuel_basic(helper: GameTestHelper) = helper.sequence {
         }
     }
 
+    /**
+     * Test calling `turtle.refuel` on non-fuels
+     */
+    @GameTest
+    fun Refuel_fail(helper: GameTestHelper) = helper.sequence {
+        val turtlePos = BlockPos(2, 2, 2)
+
+        thenOnComputer {
+            assertEquals(0, turtle.fuelLevel)
+            turtle.refuel(Optional.empty()).await().assertArrayEquals(false, "Items not combustible")
+            assertEquals(0, turtle.fuelLevel)
+        }
+        thenExecute {
+            helper.assertContainerExactly(turtlePos, listOf(ItemStack(Items.DIRT, 32)))
+        }
+    }
+
     /**
      * Test calling `turtle.refuel` with a bucket of lava
      */
diff --git a/projects/common/src/testMod/resources/data/cctest/structures/turtle_test.refuel_fail.snbt b/projects/common/src/testMod/resources/data/cctest/structures/turtle_test.refuel_fail.snbt
new file mode 100644
index 000000000..7255e040c
--- /dev/null
+++ b/projects/common/src/testMod/resources/data/cctest/structures/turtle_test.refuel_fail.snbt
@@ -0,0 +1,137 @@
+{
+    DataVersion: 2975,
+    size: [5, 5, 5],
+    data: [
+        {pos: [0, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [0, 1, 0], state: "minecraft:air"},
+        {pos: [0, 1, 1], state: "minecraft:air"},
+        {pos: [0, 1, 2], state: "minecraft:air"},
+        {pos: [0, 1, 3], state: "minecraft:air"},
+        {pos: [0, 1, 4], state: "minecraft:air"},
+        {pos: [1, 1, 0], state: "minecraft:air"},
+        {pos: [1, 1, 1], state: "minecraft:air"},
+        {pos: [1, 1, 2], state: "minecraft:air"},
+        {pos: [1, 1, 3], state: "minecraft:air"},
+        {pos: [1, 1, 4], state: "minecraft:air"},
+        {pos: [2, 1, 0], state: "minecraft:air"},
+        {pos: [2, 1, 1], state: "minecraft:air"},
+        {pos: [2, 1, 2], state: "computercraft:turtle_normal{facing:south,waterlogged:false}", nbt: {ComputerId: 1, Label: "turtle_test.refuel_fail", Fuel: 0, Items: [{Count: 32b, Slot: 0b, id: "minecraft:dirt"}], On: 1b, Owner: {LowerId: -6876936588741668278L, Name: "Dev", UpperId: 4039158846114182220L}, Slot: 0, id: "computercraft:turtle_normal"}},
+        {pos: [2, 1, 3], state: "minecraft:air"},
+        {pos: [2, 1, 4], state: "minecraft:air"},
+        {pos: [3, 1, 0], state: "minecraft:air"},
+        {pos: [3, 1, 1], state: "minecraft:air"},
+        {pos: [3, 1, 2], state: "minecraft:air"},
+        {pos: [3, 1, 3], state: "minecraft:air"},
+        {pos: [3, 1, 4], state: "minecraft:air"},
+        {pos: [4, 1, 0], state: "minecraft:air"},
+        {pos: [4, 1, 1], state: "minecraft:air"},
+        {pos: [4, 1, 2], state: "minecraft:air"},
+        {pos: [4, 1, 3], state: "minecraft:air"},
+        {pos: [4, 1, 4], state: "minecraft:air"},
+        {pos: [0, 2, 0], state: "minecraft:air"},
+        {pos: [0, 2, 1], state: "minecraft:air"},
+        {pos: [0, 2, 2], state: "minecraft:air"},
+        {pos: [0, 2, 3], state: "minecraft:air"},
+        {pos: [0, 2, 4], state: "minecraft:air"},
+        {pos: [1, 2, 0], state: "minecraft:air"},
+        {pos: [1, 2, 1], state: "minecraft:air"},
+        {pos: [1, 2, 2], state: "minecraft:air"},
+        {pos: [1, 2, 3], state: "minecraft:air"},
+        {pos: [1, 2, 4], state: "minecraft:air"},
+        {pos: [2, 2, 0], state: "minecraft:air"},
+        {pos: [2, 2, 1], state: "minecraft:air"},
+        {pos: [2, 2, 2], state: "minecraft:air"},
+        {pos: [2, 2, 3], state: "minecraft:air"},
+        {pos: [2, 2, 4], state: "minecraft:air"},
+        {pos: [3, 2, 0], state: "minecraft:air"},
+        {pos: [3, 2, 1], state: "minecraft:air"},
+        {pos: [3, 2, 2], state: "minecraft:air"},
+        {pos: [3, 2, 3], state: "minecraft:air"},
+        {pos: [3, 2, 4], state: "minecraft:air"},
+        {pos: [4, 2, 0], state: "minecraft:air"},
+        {pos: [4, 2, 1], state: "minecraft:air"},
+        {pos: [4, 2, 2], state: "minecraft:air"},
+        {pos: [4, 2, 3], state: "minecraft:air"},
+        {pos: [4, 2, 4], state: "minecraft:air"},
+        {pos: [0, 3, 0], state: "minecraft:air"},
+        {pos: [0, 3, 1], state: "minecraft:air"},
+        {pos: [0, 3, 2], state: "minecraft:air"},
+        {pos: [0, 3, 3], state: "minecraft:air"},
+        {pos: [0, 3, 4], state: "minecraft:air"},
+        {pos: [1, 3, 0], state: "minecraft:air"},
+        {pos: [1, 3, 1], state: "minecraft:air"},
+        {pos: [1, 3, 2], state: "minecraft:air"},
+        {pos: [1, 3, 3], state: "minecraft:air"},
+        {pos: [1, 3, 4], state: "minecraft:air"},
+        {pos: [2, 3, 0], state: "minecraft:air"},
+        {pos: [2, 3, 1], state: "minecraft:air"},
+        {pos: [2, 3, 2], state: "minecraft:air"},
+        {pos: [2, 3, 3], state: "minecraft:air"},
+        {pos: [2, 3, 4], state: "minecraft:air"},
+        {pos: [3, 3, 0], state: "minecraft:air"},
+        {pos: [3, 3, 1], state: "minecraft:air"},
+        {pos: [3, 3, 2], state: "minecraft:air"},
+        {pos: [3, 3, 3], state: "minecraft:air"},
+        {pos: [3, 3, 4], state: "minecraft:air"},
+        {pos: [4, 3, 0], state: "minecraft:air"},
+        {pos: [4, 3, 1], state: "minecraft:air"},
+        {pos: [4, 3, 2], state: "minecraft:air"},
+        {pos: [4, 3, 3], state: "minecraft:air"},
+        {pos: [4, 3, 4], state: "minecraft:air"},
+        {pos: [0, 4, 0], state: "minecraft:air"},
+        {pos: [0, 4, 1], state: "minecraft:air"},
+        {pos: [0, 4, 2], state: "minecraft:air"},
+        {pos: [0, 4, 3], state: "minecraft:air"},
+        {pos: [0, 4, 4], state: "minecraft:air"},
+        {pos: [1, 4, 0], state: "minecraft:air"},
+        {pos: [1, 4, 1], state: "minecraft:air"},
+        {pos: [1, 4, 2], state: "minecraft:air"},
+        {pos: [1, 4, 3], state: "minecraft:air"},
+        {pos: [1, 4, 4], state: "minecraft:air"},
+        {pos: [2, 4, 0], state: "minecraft:air"},
+        {pos: [2, 4, 1], state: "minecraft:air"},
+        {pos: [2, 4, 2], state: "minecraft:air"},
+        {pos: [2, 4, 3], state: "minecraft:air"},
+        {pos: [2, 4, 4], state: "minecraft:air"},
+        {pos: [3, 4, 0], state: "minecraft:air"},
+        {pos: [3, 4, 1], state: "minecraft:air"},
+        {pos: [3, 4, 2], state: "minecraft:air"},
+        {pos: [3, 4, 3], state: "minecraft:air"},
+        {pos: [3, 4, 4], state: "minecraft:air"},
+        {pos: [4, 4, 0], state: "minecraft:air"},
+        {pos: [4, 4, 1], state: "minecraft:air"},
+        {pos: [4, 4, 2], state: "minecraft:air"},
+        {pos: [4, 4, 3], state: "minecraft:air"},
+        {pos: [4, 4, 4], state: "minecraft:air"}
+    ],
+    entities: [],
+    palette: [
+        "minecraft:polished_andesite",
+        "minecraft:air",
+        "computercraft:turtle_normal{facing:south,waterlogged:false}"
+    ]
+}
diff --git a/projects/fabric/src/main/java/dan200/computercraft/shared/platform/PlatformHelperImpl.java b/projects/fabric/src/main/java/dan200/computercraft/shared/platform/PlatformHelperImpl.java
index 26be6593e..07f40af07 100644
--- a/projects/fabric/src/main/java/dan200/computercraft/shared/platform/PlatformHelperImpl.java
+++ b/projects/fabric/src/main/java/dan200/computercraft/shared/platform/PlatformHelperImpl.java
@@ -242,7 +242,8 @@ public List<TagKey<Item>> getDyeTags() {
 
     @Override
     public int getBurnTime(ItemStack stack) {
-        return FuelRegistry.INSTANCE.get(stack.getItem());
+        @Nullable var fuel = FuelRegistry.INSTANCE.get(stack.getItem());
+        return fuel == null ? 0 : fuel;
     }
 
     @Nullable