diff --git a/src/BasicUtils/_UpdateCallback.py b/src/BasicUtils/_UpdateCallback.py
index c7780caa4..95befebfa 100644
--- a/src/BasicUtils/_UpdateCallback.py
+++ b/src/BasicUtils/_UpdateCallback.py
@@ -53,7 +53,7 @@ class UpdateCallback:
         @param interval: number of seconds at most between the updates
         @type interval: int
         """
-        if '__call__' in dir(callback): # callback is really callable
+        if callable(callback): # callback is really callable
             self.update = self.update_real
             self.callback = callback
             self.interval = interval
diff --git a/src/plugins/ExportCSV.py b/src/plugins/ExportCSV.py
index 32173356c..2e8494eea 100644
--- a/src/plugins/ExportCSV.py
+++ b/src/plugins/ExportCSV.py
@@ -237,7 +237,7 @@ class CSVWriter:
         self.cl = cl
         self.filename = filename
         self.callback = callback
-        if '__call__' in dir(self.callback): # callback is really callable
+        if callable(self.callback): # callback is really callable
             self.update = self.update_real
         else:
             self.update = self.update_empty
diff --git a/src/plugins/ExportVCalendar.py b/src/plugins/ExportVCalendar.py
index b7939c4c6..c77c8539f 100644
--- a/src/plugins/ExportVCalendar.py
+++ b/src/plugins/ExportVCalendar.py
@@ -136,7 +136,7 @@ class CalendarWriter:
         self.cl = cl
         self.filename = filename
         self.callback = callback
-        if '__call__' in dir(self.callback): # callback is really callable
+        if callable(self.callback): # callback is really callable
             self.update = self.update_real
         else:
             self.update = self.update_empty
diff --git a/src/plugins/ExportVCard.py b/src/plugins/ExportVCard.py
index 4c9e24945..b76081c30 100644
--- a/src/plugins/ExportVCard.py
+++ b/src/plugins/ExportVCard.py
@@ -133,7 +133,7 @@ class CardWriter:
         self.cl = cl
         self.filename = filename
         self.callback = callback
-        if '__call__' in dir(self.callback): # callback is really callable
+        if callable(self.callback): # callback is really callable
             self.update = self.update_real
         else:
             self.update = self.update_empty
diff --git a/src/plugins/WriteFtree.py b/src/plugins/WriteFtree.py
index 111655a94..f1155bee7 100644
--- a/src/plugins/WriteFtree.py
+++ b/src/plugins/WriteFtree.py
@@ -141,7 +141,7 @@ class FtreeWriter:
         self.cl = cl
         self.filename = filename
         self.callback = callback
-        if '__call__' in dir(self.callback): # callback is really callable
+        if callable(self.callback): # callback is really callable
             self.update = self.update_real
         else:
             self.update = self.update_empty
diff --git a/src/plugins/WriteGeneWeb.py b/src/plugins/WriteGeneWeb.py
index 7587f04fe..a697f4f72 100644
--- a/src/plugins/WriteGeneWeb.py
+++ b/src/plugins/WriteGeneWeb.py
@@ -162,7 +162,7 @@ class GeneWebWriter:
         self.cl = cl
         self.filename = filename
         self.callback = callback
-        if '__call__' in dir(self.callback): # callback is really callable
+        if callable(self.callback): # callback is really callable
             self.update = self.update_real
         else:
             self.update = self.update_empty