diff --git a/src/Mod/Fem/importCcxDatResults.py b/src/Mod/Fem/importCcxDatResults.py
index 314a09241..d6ecf39bc 100644
--- a/src/Mod/Fem/importCcxDatResults.py
+++ b/src/Mod/Fem/importCcxDatResults.py
@@ -37,7 +37,10 @@ EIGENVALUE_OUTPUT_SECTION = "     E I G E N V A L U E   O U T P U T"
 
 ########## generic FreeCAD import and export methods ##########
 if open.__module__ == '__builtin__':
-    # because we'll redefine open below
+    # because we'll redefine open below (Python2)
+    pyopen = open
+elif open.__module__ == 'io':
+    # because we'll redefine open below (Python3)
     pyopen = open
 
 
diff --git a/src/Mod/Fem/importCcxFrdResults.py b/src/Mod/Fem/importCcxFrdResults.py
index 11968e147..608102757 100644
--- a/src/Mod/Fem/importCcxFrdResults.py
+++ b/src/Mod/Fem/importCcxFrdResults.py
@@ -39,6 +39,8 @@ import numpy as np
 ########## generic FreeCAD import and export methods ##########
 if open.__module__ == '__builtin__':
     pyopen = open  # because we'll redefine open below
+elif open.__module__ == 'io': # Python3
+    pyopen = open  # because we'll redefine open below
 
 
 def open(filename):