diff --git a/FlatCAMApp.py b/FlatCAMApp.py
index b51f55d4..fcc0f629 100644
--- a/FlatCAMApp.py
+++ b/FlatCAMApp.py
@@ -5189,7 +5189,7 @@ class App(QtCore.QObject):
             for tb in self.ui.pref_tab_area.widget(idx).findChildren(QtCore.QObject):
                 try:
                     try:
-                        tb.textEdited.disconnect()
+                        tb.textEdited.disconnect(self.on_preferences_edited)
                     except TypeError:
                         pass
                     tb.textEdited.connect(self.on_preferences_edited)
@@ -5198,7 +5198,7 @@ class App(QtCore.QObject):
 
                 try:
                     try:
-                        tb.modificationChanged.disconnect()
+                        tb.modificationChanged.disconnect(self.on_preferences_edited)
                     except TypeError:
                         pass
                     tb.modificationChanged.connect(self.on_preferences_edited)
@@ -5207,7 +5207,7 @@ class App(QtCore.QObject):
 
                 try:
                     try:
-                        tb.toggled.disconnect()
+                        tb.toggled.disconnect(self.on_preferences_edited)
                     except TypeError:
                         pass
                     tb.toggled.connect(self.on_preferences_edited)
@@ -5216,7 +5216,7 @@ class App(QtCore.QObject):
 
                 try:
                     try:
-                        tb.valueChanged.disconnect()
+                        tb.valueChanged.disconnect(self.on_preferences_edited)
                     except TypeError:
                         pass
                     tb.valueChanged.connect(self.on_preferences_edited)
@@ -5225,7 +5225,7 @@ class App(QtCore.QObject):
 
                 try:
                     try:
-                        tb.currentIndexChanged.disconnect()
+                        tb.currentIndexChanged.disconnect(self.on_preferences_edited)
                     except TypeError:
                         pass
                     tb.currentIndexChanged.connect(self.on_preferences_edited)
@@ -5241,27 +5241,27 @@ class App(QtCore.QObject):
         for idx in range(self.ui.pref_tab_area.count()):
             for tb in self.ui.pref_tab_area.widget(idx).findChildren(QtCore.QObject):
                 try:
-                    tb.textEdited.disconnect()
+                    tb.textEdited.disconnect(self.on_preferences_edited)
                 except (TypeError, AttributeError):
                     pass
 
                 try:
-                    tb.modificationChanged.disconnect()
+                    tb.modificationChanged.disconnect(self.on_preferences_edited)
                 except (TypeError, AttributeError):
                     pass
 
                 try:
-                    tb.toggled.disconnect()
+                    tb.toggled.disconnect(self.on_preferences_edited)
                 except (TypeError, AttributeError):
                     pass
 
                 try:
-                    tb.valueChanged.disconnect()
+                    tb.valueChanged.disconnect(self.on_preferences_edited)
                 except (TypeError, AttributeError):
                     pass
 
                 try:
-                    tb.currentIndexChanged.disconnect()
+                    tb.currentIndexChanged.disconnect(self.on_preferences_edited)
                 except (TypeError, AttributeError):
                     pass
 
diff --git a/README.md b/README.md
index 1a73b210..d31a0a09 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@ CAD program, and create G-Code for Isolation routing.
 - added a detection if any values are changed in the Edit -> Preferences window and on close it will ask the user if he wants to save the changes or not
 - created a new menu entry in the File menu named Recent projects that will hold the recent projects and the previous "Recent files" will hold only the previous loaded files
 - updated all translations for the new strings
+- fixed bug recently introduced that when changing the units in the Edit -> Preferences it did not converted the values
 - RELEASE 8.92
 
 30.07.2019