diff --git a/README.MD b/README.MD
index 069b925..25df0f3 100644
--- a/README.MD
+++ b/README.MD
@@ -22,6 +22,7 @@ This mod also contains patches for the following mods:
 - CoFH Lib
 - DragonAPI
 - GalactiCraft
+- Immersive Cavegen
 - More Fun Quicksand Mod
 - Nature's Compass
 - Realistic Terrain Generation
diff --git a/dependencies.gradle b/dependencies.gradle
index 7a4d842..c7ba456 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -19,6 +19,7 @@ dependencies {
     compile(deobfMaven(curseMaven, "curse.maven:rtg-237989:2521557")) // 1.1.1.7
     compile(deobfMaven(curseMaven, "curse.maven:naturescompass-252848:2451823")) // 1.3.1
     compile(deobfMaven(curseMaven, "curse.maven:dynamicsurrounding-238891:2642381")) // 1.0.6.4
+    compile(deobfMaven(curseMaven, "curse.maven:immersivecavegen-521557:3649411")) // 1.2g
     compile(files("lib/archaicfix-mc1.7.10-3d1392f-dev.jar"))
     compileOnly(files("lib/GalacticraftCore-1.7-3.0.12.504-deobf.jar"))
 }
diff --git a/src/main/java/com/falsepattern/endlessids/mixin/mixins/common/icg/MysteriumPatchesFixesCaveMixin.java b/src/main/java/com/falsepattern/endlessids/mixin/mixins/common/icg/MysteriumPatchesFixesCaveMixin.java
new file mode 100644
index 0000000..8edbaef
--- /dev/null
+++ b/src/main/java/com/falsepattern/endlessids/mixin/mixins/common/icg/MysteriumPatchesFixesCaveMixin.java
@@ -0,0 +1,19 @@
+package com.falsepattern.endlessids.mixin.mixins.common.icg;
+
+import com.falsepattern.endlessids.constants.ExtendedConstants;
+import com.falsepattern.endlessids.constants.VanillaConstants;
+import net.tclproject.mysteriumlib.asm.fixes.MysteriumPatchesFixesCave;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.Constant;
+import org.spongepowered.asm.mixin.injection.ModifyConstant;
+
+@Mixin(value = MysteriumPatchesFixesCave.class,
+       remap = false)
+public abstract class MysteriumPatchesFixesCaveMixin {
+    @ModifyConstant(method = "<clinit>",
+                    constant = @Constant(intValue = VanillaConstants.biomeIDCount),
+                    require = 1)
+    private static int extendIDs(int constant) {
+        return ExtendedConstants.biomeIDCount;
+    }
+}
diff --git a/src/main/java/com/falsepattern/endlessids/mixin/plugin/Mixin.java b/src/main/java/com/falsepattern/endlessids/mixin/plugin/Mixin.java
index 268643a..c7b4593 100644
--- a/src/main/java/com/falsepattern/endlessids/mixin/plugin/Mixin.java
+++ b/src/main/java/com/falsepattern/endlessids/mixin/plugin/Mixin.java
@@ -89,6 +89,10 @@ public enum Mixin implements IMixin {
     GalactiCraftCoreConfigManagerCoreMixin(Side.COMMON, require(TargetedMod.GALACTICRAFTCORE),
                                            "galacticraft.ConfigManagerCoreMixin"),
     //endregion GalactiCraftCore->common
+    //region ICG->common
+    ICGMysteriumPatchesFixesCaveMixin(Side.COMMON, require(TargetedMod.ICG),
+                                      "icg.MysteriumPatchesFixesCaveMixin"),
+    //endregion ICG->common
     //region MFQM->common
     MFQMMixin(Side.COMMON, require(TargetedMod.MFQM), "mfqm.MFQMMixin"),
     MFQMDataWatcherMixin(Side.COMMON, require(TargetedMod.MFQM).and(condition(() -> IEConfig.extendDataWatcher)),
diff --git a/src/main/java/com/falsepattern/endlessids/mixin/plugin/TargetedMod.java b/src/main/java/com/falsepattern/endlessids/mixin/plugin/TargetedMod.java
index fab2f6e..6852f74 100644
--- a/src/main/java/com/falsepattern/endlessids/mixin/plugin/TargetedMod.java
+++ b/src/main/java/com/falsepattern/endlessids/mixin/plugin/TargetedMod.java
@@ -17,6 +17,7 @@ public enum TargetedMod implements ITargetedMod {
     COFHLIB("CoFH Lib", true, startsWith("cofhlib-")),
     DRAGONAPI("DragonAPI", false, startsWith("dragonapi")),
     GALACTICRAFTCORE("GalactiCraftCore", false, startsWith("galacticraftcore")),
+    ICG("Immersive Cavegen", true, startsWith("immersivecavegen")),
     MFQM("More Fun Quicksand Mod", false, startsWith("morefunquicksandmod-")),
     NATURESCOMPASS("Nature's Compass", true, startsWith("naturescompass")),
     RTG("Realistic Terrain Generation", true, startsWith("rtg-")),