diff --git a/src/wireviz.py b/src/wireviz.py
index 650acf2..551c388 100755
--- a/src/wireviz.py
+++ b/src/wireviz.py
@@ -341,6 +341,8 @@ class Connector:
                 self.pincount = len(self.pinout)
             elif self.pinnumbers:
                 self.pincount = len(self.pinnumbers)
+            elif self.category == 'ferrule':
+                self.pincount = 1
             else:
                 raise Exception('You need to specify at least one, pincount, pinout or pinnumbers')