diff --git a/sdb/command.py b/sdb/command.py
index 9d5e09df..83603cca 100644
--- a/sdb/command.py
+++ b/sdb/command.py
@@ -145,7 +145,7 @@ def help(cls, name: str) -> None:
             # conditional control flow.
             #
             # pylint: disable=unsubscriptable-object
-            it_text = f"This command accepts inputs of type 'void *',"
+            it_text = "This command accepts inputs of type 'void *',"
             if cls.input_type[-1] == '*':
                 it_text += f" and '{cls.input_type[:-1].strip()}',"
             it_text += f" which will be converted to '{cls.input_type}'."
diff --git a/sdb/commands/zfs/histograms.py b/sdb/commands/zfs/histograms.py
index aea150c8..9f983b57 100644
--- a/sdb/commands/zfs/histograms.py
+++ b/sdb/commands/zfs/histograms.py
@@ -143,7 +143,7 @@ def print_histogram(hist: drgn.Object,
 
     def _call(self, objs: Iterable[drgn.Object]) -> None:
         for obj in objs:
-            print(f'seg-size   count')
+            print('seg-size   count')
             print(f'{"-" * 8}   {"-" * 5}')
             ZFSHistogram.print_histogram(obj, self.args.offset)
             ZFSHistogram.print_histogram_median(obj, self.args.offset)