diff --git a/src/DIRAC/Resources/Computing/BatchSystems/Condor.py b/src/DIRAC/Resources/Computing/BatchSystems/Condor.py
index b5c6644bedf..08b48534259 100644
--- a/src/DIRAC/Resources/Computing/BatchSystems/Condor.py
+++ b/src/DIRAC/Resources/Computing/BatchSystems/Condor.py
@@ -170,7 +170,7 @@ def submitJob(self, **kwargs):
         submitOptions = kwargs["SubmitOptions"]
         preamble = kwargs.get("Preamble")
 
-        jdlFile = tempfile.NamedTemporaryFile(dir=outputDir, suffix=".jdl")
+        jdlFile = tempfile.NamedTemporaryFile(dir=outputDir, suffix=".jdl", mode="wt")
         scheddOptions = 'requirements = OpSys == "LINUX"\n'
         scheddOptions += "gentenv = False"
         jdlFile.write(