diff --git a/db/migrate/20240601155348_dedup_item_requests_in_requests.rb b/db/migrate/20240601155348_dedup_item_requests_in_requests.rb
new file mode 100644
index 0000000000..6ff7adaae5
--- /dev/null
+++ b/db/migrate/20240601155348_dedup_item_requests_in_requests.rb
@@ -0,0 +1,58 @@
+class DedupItemRequestsInRequests < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def up
+    # There's some really gross request data in Jan 2023 and earlier
+    # that we don't want to get swept up in this migration. We'll need
+    # to fix it some day but for now we'll make recent-ish, well-formed
+    # data obey the dedup requirement, which will reduce weird edge
+    # cases when fulfilling requests + editing distributions.
+    start_date = Date.new(2023, 6, 1)
+
+    Request.where(created_at: start_date..).find_each do |request|
+      grouped_item_requests = request.item_requests.to_a.group_by(&:item_id)
+
+      if grouped_item_requests.values.all? { |item_requests| item_requests.length == 1 }
+        next
+      end
+
+      Request.transaction do
+        request_items = grouped_item_requests.map do |item_id, item_requests|
+          if item_requests.length == 1
+            next {
+              item_id: item_id,
+              quantity: item_requests.first.quantity
+            }
+          end
+
+          quantity = item_requests.map { |item_request| item_request.quantity.to_i }.sum.to_s
+          children = item_requests.flat_map(&:children).uniq
+
+          primary_item_request = item_requests.shift
+
+          # If item_requests isn't empty, then there were more
+          # item_requests with that same item_id
+          if !item_requests.empty?
+            primary_item_request.update!(
+              quantity: quantity,
+              children: children
+            )
+
+            item_requests.each(&:destroy!)
+          end
+
+          {
+            item_id: item_id,
+            quantity: quantity
+          }
+        end
+
+        request.reload.update!(request_items: request_items)
+      end
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 43a05b86c3..3ac916c5e4 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_05_19_201258) do
+ActiveRecord::Schema[7.1].define(version: 2024_06_01_155348) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"