diff --git a/forge/build.gradle b/forge/build.gradle
index d304ab3d..5344f33d 100644
--- a/forge/build.gradle
+++ b/forge/build.gradle
@@ -61,6 +61,7 @@ dependencies {
     modCompileOnly("curse.maven:supermartijncore-454372:4455391")
     modCompileOnly("vazkii.patchouli:Patchouli:1.19.2-77")
     modCompileOnly("curse.maven:cofhcore-69162:5374122")
+    modCompileOnly("curse.maven:resourcefullib-570073:5659871")
 
     // runtime remapping at home
     for (extraModJar in fileTree(dir: extraModsDir, include: '*.jar')) {
diff --git a/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/resourcefullib_highlight_deduplication/HighlightHandlerMixin.java b/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/resourcefullib_highlight_deduplication/HighlightHandlerMixin.java
new file mode 100644
index 00000000..157e694d
--- /dev/null
+++ b/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/resourcefullib_highlight_deduplication/HighlightHandlerMixin.java
@@ -0,0 +1,69 @@
+package org.embeddedt.modernfix.forge.mixin.perf.resourcefullib_highlight_deduplication;
+
+import com.teamresourceful.resourcefullib.client.highlights.HighlightHandler;
+import com.teamresourceful.resourcefullib.client.highlights.base.Highlight;
+import com.teamresourceful.resourcefullib.client.highlights.base.HighlightLine;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+import net.minecraft.world.level.block.state.BlockState;
+import org.embeddedt.modernfix.ModernFix;
+import org.embeddedt.modernfix.annotation.ClientOnlyMixin;
+import org.embeddedt.modernfix.annotation.RequiresMod;
+import org.joml.Vector3f;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+@Mixin(HighlightHandler.class)
+@RequiresMod("resourcefullib")
+@ClientOnlyMixin
+public class HighlightHandlerMixin {
+    @Inject(method = "apply(Ljava/util/Map;Lnet/minecraft/server/packs/resources/ResourceManager;Lnet/minecraft/util/profiling/ProfilerFiller;)V", at = @At("RETURN"), remap = false)
+    private void deduplicateHighlights(CallbackInfo ci) {
+        Map<BlockState, Highlight> stateCache;
+
+        try {
+            var stateCacheMap = this.getClass().getDeclaredField("STATE_CACHE");
+            if (stateCacheMap.get(null) instanceof HashMap<?,?> hashMap) {
+                stateCache = (Map<BlockState, Highlight>)hashMap;
+            } else {
+                throw new ReflectiveOperationException("Unexpected map type");
+            }
+        } catch (ReflectiveOperationException e) {
+            ModernFix.LOGGER.error("Not applying Resourceful Lib patch due to reflection error", e);
+            return;
+        }
+
+        ObjectOpenHashSet<Vector3f> pointCache = new ObjectOpenHashSet<>();
+        ObjectOpenHashSet<HighlightLine> lineCache = new ObjectOpenHashSet<>();
+        ObjectOpenHashSet<List<HighlightLine>> listCache = new ObjectOpenHashSet<>();
+        Function<HighlightLine, HighlightLine> deduplicator = l -> {
+            if (!lineCache.contains(l)) {
+                l = new HighlightLine(
+                        pointCache.addOrGet(l.start()),
+                        pointCache.addOrGet(l.end()),
+                        pointCache.addOrGet(l.normal())
+                );
+            }
+            return lineCache.addOrGet(l);
+        };
+
+        stateCache.replaceAll((rl, highlight) -> {
+            if (highlight == null) {
+                return null;
+            }
+            List<HighlightLine> newList = highlight.lines();
+            if (!listCache.contains(newList)) {
+                newList = newList.stream().map(deduplicator).toList();
+            }
+            return new Highlight(highlight.id(), listCache.addOrGet(newList));
+        });
+
+        ModernFix.LOGGER.info("Deduplicated ResourcefulLib highlights ({} points, {} lines)", pointCache.size(), lineCache.size());
+    }
+}