diff --git a/lawluigi_configs/KingMaker_luigi.cfg b/lawluigi_configs/KingMaker_luigi.cfg
index 709ac56..e525db1 100644
--- a/lawluigi_configs/KingMaker_luigi.cfg
+++ b/lawluigi_configs/KingMaker_luigi.cfg
@@ -51,6 +51,13 @@ only_missing = True
 ; bootstrap file to be sourced at beginning of htcondor jobs (relative PATH to framework.py)
 bootstrap_file = setup_law_remote.sh
 files_per_task = 10
+
+; If some datasets are known to result in files with a large number of events, a lower number 
+; of files per task can be set for these datasets to avoid long runtimes. This is a mapping
+; based on dataset name to number of files per task following "sample_type" key of
+; sample_database collection, e.g., {"ttbar": 3, "wjets": 20}.
+custom_files_per_task = {}
+
 ; scopes and shifts are to be provided in the config, or as command line arguments via --scope and --shift
 ; in both cases, the values are expected to be comma-separated lists without spaces or quotes
 scopes = mt,et
@@ -112,4 +119,4 @@ friend_mapping = {}
 silent = True
 ; set to False to print out the datasets
 
-[QuantitiesMap]
\ No newline at end of file
+[QuantitiesMap]
diff --git a/processor/framework.py b/processor/framework.py
index 842e437..8763569 100644
--- a/processor/framework.py
+++ b/processor/framework.py
@@ -73,8 +73,8 @@ class Task(law.Task):
         description="Tag to differentiate workflow runs. Set to a timestamp as default.",
     )
     nanoAOD_version = luigi.Parameter(
-        default=NanoAODVersions.v12.value,
-        description="Version of the NanoAOD files that are used in the analysis. 'NanoAOD_v12' is the default.",
+        default=NanoAODVersions.v15.value,
+        description="Version of the NanoAOD files that are used in the analysis. 'NanoAOD_v15' is the default.",
     )
 
     # Ensure that branch parameter is processed normally
diff --git a/processor/tasks/CROWNBase.py b/processor/tasks/CROWNBase.py
index 695cce5..0696f88 100644
--- a/processor/tasks/CROWNBase.py
+++ b/processor/tasks/CROWNBase.py
@@ -152,6 +152,11 @@ class CROWNExecuteBase(HTCondorWorkflow, law.LocalWorkflow):
     analysis = luigi.Parameter()
     config = luigi.Parameter()
     files_per_task = luigi.IntParameter()
+    custom_files_per_task = luigi.DictParameter(
+        default={},
+        significant=False,
+        description="Map specific sample_types to custom files_per_task",
+    )
 
     def htcondor_output_directory(self):
         return law.LocalDirectoryTarget(self.local_path(f"htcondor_files/{self.nick}"))
diff --git a/processor/tasks/CROWNRun.py b/processor/tasks/CROWNRun.py
index f09fe45..2d7463a 100644
--- a/processor/tasks/CROWNRun.py
+++ b/processor/tasks/CROWNRun.py
@@ -45,6 +45,9 @@ def create_branch_map(self):
         if len(inputdata["filelist"]) == 0:
             raise Exception("No files found for dataset {}".format(self.nick))
         files_per_task = self.files_per_task
+        custom_fpt = self.custom_files_per_task.get(self.sample_type)
+        if custom_fpt is not None:
+            files_per_task = int(custom_fpt)
         if self.sample_type == "data" and any(
             era in self.nick for era in self.problematic_eras
         ):