diff --git a/wahoomc/osm_maps_functions.py b/wahoomc/osm_maps_functions.py
index 24bcdb83..890df227 100644
--- a/wahoomc/osm_maps_functions.py
+++ b/wahoomc/osm_maps_functions.py
@@ -421,7 +421,7 @@ def split_filtered_country_files_to_tiles(self):
                     cmd.append('-o='+out_file_names)
 
                     run_subprocess_and_log_output(
-                        cmd, '! Error in osmconvert with country: {country}. Win/out_file_names')
+                        cmd, f'! Error in osmconvert with country: {country}. Win/out_file_names')
 
                 # Non-Windows
                 else:
@@ -434,7 +434,7 @@ def split_filtered_country_files_to_tiles(self):
                     cmd.extend(['--overwrite'])
 
                     run_subprocess_and_log_output(
-                        cmd, '! Error in Osmium with country: {country}. macOS/out_file')
+                        cmd, f'! Error in Osmium with country: {country}. macOS/out_file')
 
                     cmd = ['osmium', 'extract']
                     cmd.extend(
@@ -445,7 +445,7 @@ def split_filtered_country_files_to_tiles(self):
                     cmd.extend(['--overwrite'])
 
                     run_subprocess_and_log_output(
-                        cmd, '! Error in Osmium with country: {country}. macOS/out_file_names')
+                        cmd, f'! Error in Osmium with country: {country}. macOS/out_file_names')
 
                 self.log_tile_debug(tile["x"], tile["y"], tile_count, f'{country} {timings_tile.stop_and_return()}')