diff --git a/tools/oneclick/gui/unb_gui_commands.py b/tools/oneclick/gui/unb_gui_commands.py
index b8904e40d02465c525d0d0c63fd5c23c20737c1d..6d03441bccd562b39e08ef77a113df480a00fce2 100644
--- a/tools/oneclick/gui/unb_gui_commands.py
+++ b/tools/oneclick/gui/unb_gui_commands.py
@@ -367,11 +367,11 @@ class Commands:
     # check rbf file name for 'bn_'/'fn_'
     def check_rbf(self, rbf_path):
         rbf_name = rbf_path.split('/')[-1]
-        if ('bn_' in rbf_name) and not (self.fn_nrs.get == ''):
+        if ('bn_' in rbf_name) and not (self.fn_nrs.get() == ''):
             tkMessageBox.showwarning("Warning","You can't flash front nodes with a rbf for backnodes")            
             return False
             
-        elif ('fn_' in rbf_name) and not (self.bn_nrs.get == ''):
+        elif ('fn_' in rbf_name) and not (self.bn_nrs.get() == ''):
             tkMessageBox.showwarning("Warning","You can't flash back nodes with a rbf for frontnodes")            
             return False