diff --git a/src/main/java/turniplabs/halplibe/helper/BlockHelper.java b/src/main/java/turniplabs/halplibe/helper/BlockHelper.java
index 729ebc7..613a830 100644
--- a/src/main/java/turniplabs/halplibe/helper/BlockHelper.java
+++ b/src/main/java/turniplabs/halplibe/helper/BlockHelper.java
@@ -56,18 +56,20 @@ public static int findLength(int id, int terminate) {
 
     /**
      * Allows halplibe to automatically figure out where to insert the runs
+     * @param modid     an identifier for the mod, can be anything, but should be something the user can identify
      * @param runs      a toml object representing configured registry runs
      * @param neededIds the number of needed ids
      *                  if this changes after the mod has been configured (i.e. mod updated and now has more blocks) it'll find new, valid runs to put those blocks into
      * @param function  the function to run for registering items
      */
-    public static void reserveRuns(Toml runs, int neededIds, Consumer<IdSupplier> function) {
+    public static void reserveRuns(String modid, Toml runs, int neededIds, Consumer<IdSupplier> function) {
         RunLengthConfig cfg = new RunLengthConfig(runs, neededIds);
         cfg.register(reserves);
         RegistryHelper.scheduleSmartRegistry(
                 () -> {
-                    IdSupplier supplier = new IdSupplier(reserves, cfg, neededIds);
+                    IdSupplier supplier = new IdSupplier(modid, reserves, cfg, neededIds);
                     function.accept(supplier);
+                    supplier.validate();
                 }
         );
     }
diff --git a/src/main/java/turniplabs/halplibe/helper/ItemHelper.java b/src/main/java/turniplabs/halplibe/helper/ItemHelper.java
index e733a5f..83b2f06 100644
--- a/src/main/java/turniplabs/halplibe/helper/ItemHelper.java
+++ b/src/main/java/turniplabs/halplibe/helper/ItemHelper.java
@@ -57,18 +57,20 @@ public static int findLength(int id, int terminate) {
 
 	/**
 	 * Allows halplibe to automatically figure out where to insert the runs
+	 * @param modid     an identifier for the mod, can be anything, but should be something the user can identify
 	 * @param runs      a toml object representing configured registry runs
 	 * @param neededIds the number of needed ids
 	 *                  if this changes after the mod has been configured (i.e. mod updated and now has more items) it'll find new, valid runs to put those items into
 	 * @param function  the function to run for registering items
 	 */
-	public static void reserveRuns(Toml runs, int neededIds, Consumer<IdSupplier> function) {
+	public static void reserveRuns(String modid, Toml runs, int neededIds, Consumer<IdSupplier> function) {
 		RunLengthConfig cfg = new RunLengthConfig(runs, neededIds);
 		cfg.register(reserves);
 		RegistryHelper.scheduleSmartRegistry(
 				() -> {
-					IdSupplier supplier = new IdSupplier(reserves, cfg, neededIds);
+					IdSupplier supplier = new IdSupplier(modid, reserves, cfg, neededIds);
 					function.accept(supplier);
+					supplier.validate();
 				}
 		);
 	}
diff --git a/src/main/java/turniplabs/halplibe/util/registry/IdSupplier.java b/src/main/java/turniplabs/halplibe/util/registry/IdSupplier.java
index 50e0005..435b86e 100644
--- a/src/main/java/turniplabs/halplibe/util/registry/IdSupplier.java
+++ b/src/main/java/turniplabs/halplibe/util/registry/IdSupplier.java
@@ -1,11 +1,13 @@
 package turniplabs.halplibe.util.registry;
 
-import turniplabs.halplibe.util.registry.error.RequestOutOfBounds;
+import turniplabs.halplibe.util.registry.error.RequestCutShortException;
+import turniplabs.halplibe.util.registry.error.RequestOutOfBoundsException;
 
 import java.util.ArrayList;
 import java.util.List;
 
 public class IdSupplier {
+    String modid;
     RunReserves reserves;
     RunLengthConfig cfg;
     int max;
@@ -15,7 +17,8 @@ public class IdSupplier {
     /* if this is true, the reservations will get optimized when being written */
     boolean hasUnreserved = false;
 
-    public IdSupplier(RunReserves reserves, RunLengthConfig cfg, int max) {
+    public IdSupplier(String modid, RunReserves reserves, RunLengthConfig cfg, int max) {
+        this.modid = modid;
         this.reserves = reserves;
         this.cfg = cfg;
         this.max = max;
@@ -80,7 +83,7 @@ public int next() {
         }
 
         if (done > max) {
-            throw new RequestOutOfBounds("A mod has gotten more ids than it has requested.");
+            throw new RequestOutOfBoundsException(modid + " has grabbed more ids than it has requested.");
         }
 
         done++;
@@ -152,4 +155,10 @@ public void ensureFree(int amount) {
         reservationEnd = reservationStart + reserves.runLengthFinder.apply(reservationStart, max - done);
         current = 0;
     }
+
+    public void validate() {
+        if (done != max) {
+            throw new RequestCutShortException(modid + " did not use up all requested ids.");
+        }
+    }
 }
diff --git a/src/main/java/turniplabs/halplibe/util/registry/error/RequestCutShortException.java b/src/main/java/turniplabs/halplibe/util/registry/error/RequestCutShortException.java
new file mode 100644
index 0000000..7836556
--- /dev/null
+++ b/src/main/java/turniplabs/halplibe/util/registry/error/RequestCutShortException.java
@@ -0,0 +1,7 @@
+package turniplabs.halplibe.util.registry.error;
+
+public class RequestCutShortException extends RuntimeException {
+    public RequestCutShortException(String message) {
+        super(message);
+    }
+}
diff --git a/src/main/java/turniplabs/halplibe/util/registry/error/RequestOutOfBounds.java b/src/main/java/turniplabs/halplibe/util/registry/error/RequestOutOfBounds.java
deleted file mode 100644
index 0a81fd3..0000000
--- a/src/main/java/turniplabs/halplibe/util/registry/error/RequestOutOfBounds.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package turniplabs.halplibe.util.registry.error;
-
-public class RequestOutOfBounds extends RuntimeException {
-    public RequestOutOfBounds(String message) {
-        super(message);
-    }
-}
diff --git a/src/main/java/turniplabs/halplibe/util/registry/error/RequestOutOfBoundsException.java b/src/main/java/turniplabs/halplibe/util/registry/error/RequestOutOfBoundsException.java
new file mode 100644
index 0000000..4d71098
--- /dev/null
+++ b/src/main/java/turniplabs/halplibe/util/registry/error/RequestOutOfBoundsException.java
@@ -0,0 +1,7 @@
+package turniplabs.halplibe.util.registry.error;
+
+public class RequestOutOfBoundsException extends RuntimeException {
+    public RequestOutOfBoundsException(String message) {
+        super(message);
+    }
+}