diff --git a/spec/models/lettings_log_derived_fields_spec.rb b/spec/models/lettings_log_derived_fields_spec.rb
index e49e045a6..c7444a956 100644
--- a/spec/models/lettings_log_derived_fields_spec.rb
+++ b/spec/models/lettings_log_derived_fields_spec.rb
@@ -1232,4 +1232,20 @@ RSpec.describe LettingsLog, type: :model do
       expect { log.set_derived_fields! }.to not_change(log, :ecstat2)
     end
   end
+
+  describe "deriving num of bedrooms from whether property is bedsit" do
+    it "sets num of bedrooms to 1 when property is a bedsit" do
+      log.unittype_gn = 2
+      expect { log.set_derived_fields! }.to change(log, :beds).to 1
+    end
+
+    it "sets num of bedrooms to nil when property is change from a bedsit" do
+      log.unittype_gn = 2
+      log.set_derived_fields!
+      log.clear_changes_information
+
+      log.unittype_gn = 1
+      expect { log.set_derived_fields! }.to change(log, :beds).to nil
+    end
+  end
 end
diff --git a/spec/models/sales_log_derived_fields_spec.rb b/spec/models/sales_log_derived_fields_spec.rb
index 7827ce282..f1be79fff 100644
--- a/spec/models/sales_log_derived_fields_spec.rb
+++ b/spec/models/sales_log_derived_fields_spec.rb
@@ -186,5 +186,23 @@ RSpec.describe SalesLog, type: :model do
         end
       end
     end
+
+    describe "deriving num of bedrooms from whether property is bedsit" do
+      let(:log) { create(:sales_log, :completed) }
+
+      it "sets num of bedrooms to 1 when property is a bedsit" do
+        log.proptype = 2
+        expect { log.set_derived_fields! }.to change(log, :beds).to 1
+      end
+
+      it "sets num of bedrooms to nil when property is change from a bedsit" do
+        log.proptype = 2
+        log.set_derived_fields!
+        log.clear_changes_information
+
+        log.proptype = 1
+        expect { log.set_derived_fields! }.to change(log, :beds).to nil
+      end
+    end
   end
 end