diff --git a/tracetools_analysis/tracetools_analysis/data_model/cpu_time.py b/tracetools_analysis/tracetools_analysis/data_model/cpu_time.py
index 5c10e5f..07dece0 100644
--- a/tracetools_analysis/tracetools_analysis/data_model/cpu_time.py
+++ b/tracetools_analysis/tracetools_analysis/data_model/cpu_time.py
@@ -49,7 +49,7 @@ class CpuTimeDataModel(DataModel):
             'duration': duration,
             'cpu_id': cpu_id,
         }
-        self.times.loc[len(self.times.index)] = data
+        self.times = self.times.append(data, ignore_index=True)
 
     def print_model(self) -> None:
         """Debug method to print every contained df."""
diff --git a/tracetools_analysis/tracetools_analysis/data_model/profile.py b/tracetools_analysis/tracetools_analysis/data_model/profile.py
index 1648cd6..6a8a027 100644
--- a/tracetools_analysis/tracetools_analysis/data_model/profile.py
+++ b/tracetools_analysis/tracetools_analysis/data_model/profile.py
@@ -59,7 +59,7 @@ class ProfileDataModel(DataModel):
             'duration': duration,
             'actual_duration': actual_duration,
         }
-        self.times.loc[len(self.times.index)] = data
+        self.times = self.times.append(data, ignore_index=True)
 
     def print_model(self) -> None:
         """Debug method to print every contained df."""
diff --git a/tracetools_analysis/tracetools_analysis/data_model/ros.py b/tracetools_analysis/tracetools_analysis/data_model/ros.py
index ac4ae18..e1064db 100644
--- a/tracetools_analysis/tracetools_analysis/data_model/ros.py
+++ b/tracetools_analysis/tracetools_analysis/data_model/ros.py
@@ -143,7 +143,7 @@ class RosDataModel(DataModel):
             'duration': duration,
             'intra_process': intra_process,
         }
-        self.callback_instances.loc[len(self.callback_instances.index)] = data
+        self.callback_instances = self.callback_instances.append(data, ignore_index=True)
 
     def print_model(self) -> None:
         """Debug method to print every contained df."""