diff --git a/dataserv/Farmer.py b/dataserv/Farmer.py
index 5a7ef87..079e99a 100644
--- a/dataserv/Farmer.py
+++ b/dataserv/Farmer.py
@@ -56,7 +56,7 @@ def validate(self):
         if not self.is_btc_address():
             raise ValueError("Invalid BTC Address.")
         elif self.exists():
-            raise ValueError("Address Already Is Registered.")
+            raise LookupError("Address Already Is Registered.")
 
     def register(self):
         """Add the farmer to the database."""
diff --git a/dataserv/app.py b/dataserv/app.py
index cbb8511..9aca2b1 100644
--- a/dataserv/app.py
+++ b/dataserv/app.py
@@ -17,16 +17,16 @@ def register(btc_addr):
     # create Farmer object to represent user
     user = Farmer(btc_addr)
 
+    # error template
+    error_msg = "Registration Failed: {0}"
+
     # attempt to register the farmer/farming address
     try:
         user.register()
         return make_response("User registered.", 200)
     except ValueError as e:
-        error_msg = "Registration Failed: {0}"
-
-        if str(e) == "Invalid BTC Address.":
             return make_response(error_msg.format(e), 400)
-        elif str(e) == "Address Already Is Registered.":
+    except LookupError as e:
             return make_response(error_msg.format(e), 409)
 
 
diff --git a/tests/test_Farmer.py b/tests/test_Farmer.py
index e46716b..17629b0 100644
--- a/tests/test_Farmer.py
+++ b/tests/test_Farmer.py
@@ -41,7 +41,7 @@ def test_register(self):
         self.assertTrue(farmer1.exists())
 
         # test duplicate
-        self.assertRaises(ValueError, farmer1.register)
+        self.assertRaises(LookupError, farmer1.register)
 
         # these should not be inserted
         self.assertRaises(ValueError, farmer2.register)