diff --git a/gui/gui_classic.py b/gui/gui_classic.py
index ef2958b27..0b28f4e72 100644
--- a/gui/gui_classic.py
+++ b/gui/gui_classic.py
@@ -1131,10 +1131,7 @@ class ElectrumWindow(QMainWindow):
 
         for address in self.wallet.addressbook:
             label = self.wallet.labels.get(address,'')
-            n = 0 
-            for tx in self.wallet.transactions.values():
-                if address in map(lambda x: x[0], tx.outputs): n += 1
-            
+            n = self.wallet.get_num_tx(address)
             item = QTreeWidgetItem( [ address, label, "%d"%n] )
             item.setFont(0, QFont(MONOSPACE_FONT))
             # 32 = label can be edited (bool)
diff --git a/gui/gui_gtk.py b/gui/gui_gtk.py
index 55b934235..88de6ec5b 100644
--- a/gui/gui_gtk.py
+++ b/gui/gui_gtk.py
@@ -1152,10 +1152,7 @@ class ElectrumWindow:
             
         for address in self.wallet.addressbook:
             label = self.wallet.labels.get(address)
-            n = 0 
-            for tx in self.wallet.transactions.values():
-                if address in map(lambda x:x[0], tx.outputs): n += 1
-
+            n = self.wallet.get_num_tx(address)
             self.addressbook_list.append((address, label, "%d"%n))
 
     def update_history_tab(self):
diff --git a/lib/wallet.py b/lib/wallet.py
index 9e3b5197d..b39770eec 100644
--- a/lib/wallet.py
+++ b/lib/wallet.py
@@ -407,6 +407,12 @@ class Wallet:
         # redo labels
         # self.update_tx_labels()
 
+    def get_num_tx(self, address):
+        n = 0 
+        for tx in self.transactions.values():
+            if address in map(lambda x:x[0], tx.outputs): n += 1
+        return n
+
 
     def get_address_flags(self, addr):
         flags = "C" if self.is_change(addr) else "I" if addr in self.imported_keys.keys() else "-"