diff --git a/CHANGELOG.md b/CHANGELOG.md
index 14ddabb..9063833 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,8 +7,10 @@ and this project adheres to [Semantic Versioning].
 
 ## Unreleased
 
+- added better logging for cases where items are assigned to multiple unification tags
 - fixed crash when runtime isn't loaded ([#101](https://github.com/AlmostReliable/almostunified/issues/101))
 - fixed newly created custom tags not being considered for unification
+- fixed runtime not being available when items are assigned to multiple unification tags
 
 ## [1.2.0] - 2024-10-06
 
diff --git a/Common/src/main/java/com/almostreliable/unified/unification/UnificationLookupImpl.java b/Common/src/main/java/com/almostreliable/unified/unification/UnificationLookupImpl.java
index e7041cd..991489a 100644
--- a/Common/src/main/java/com/almostreliable/unified/unification/UnificationLookupImpl.java
+++ b/Common/src/main/java/com/almostreliable/unified/unification/UnificationLookupImpl.java
@@ -7,6 +7,7 @@ import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.crafting.Ingredient;
 
+import com.almostreliable.unified.AlmostUnifiedCommon;
 import com.almostreliable.unified.api.unification.ModPriorities;
 import com.almostreliable.unified.api.unification.StoneVariants;
 import com.almostreliable.unified.api.unification.TagSubstitutions;
@@ -117,15 +118,22 @@ public final class UnificationLookupImpl implements UnificationLookup {
 
     public static class Builder {
 
-        private final Set<UnificationEntry<Item>> createdEntries = new HashSet<>();
+        private final Map<UnificationEntry<Item>, TagKey<Item>> entriesToTags = new HashMap<>();
         private final Map<TagKey<Item>, Set<UnificationEntry<Item>>> tagsToEntries = new HashMap<>();
 
         private void put(TagKey<Item> tag, UnificationEntry<Item> entry) {
-            if (createdEntries.contains(entry)) {
-                throw new IllegalStateException("entry " + entry + " already created");
+            if (entriesToTags.containsKey(entry)) {
+                var boundTag = entriesToTags.get(entry);
+                AlmostUnifiedCommon.LOGGER.error(
+                    "Unification entry for item '{}' with tag '#{}' is already part of tag '#{}'.",
+                    entry.id(),
+                    tag.location(),
+                    boundTag.location()
+                );
+                return;
             }
 
-            createdEntries.add(entry);
+            entriesToTags.put(entry, tag);
             tagsToEntries.computeIfAbsent(tag, $ -> new HashSet<>()).add(entry);
         }