diff --git a/data_prep/introspector.py b/data_prep/introspector.py
index 9972f172ae..d472b1b42a 100755
--- a/data_prep/introspector.py
+++ b/data_prep/introspector.py
@@ -732,7 +732,7 @@ def populate_benchmarks_using_introspector(project: str, language: str,
 
     if len(potential_benchmarks) >= (limit * len(target_oracles)):
       break
-  logger.info("Length of potential targets: %d" % (len(potential_benchmarks)))
+  logger.info('Length of potential targets: %d', len(potential_benchmarks))
 
   return potential_benchmarks
 
diff --git a/run_all_experiments.py b/run_all_experiments.py
index bcf1a9cdc8..b24394fbc6 100755
--- a/run_all_experiments.py
+++ b/run_all_experiments.py
@@ -54,7 +54,8 @@
 TIME_STAMP_FMT = '%Y-%m-%d %H:%M:%S'
 
 LOG_LEVELS = {'debug', 'info'}
-LOG_FMT = '%(asctime)s.%(msecs)03d %(levelname)s %(module)s - %(funcName)s: %(message)s'
+LOG_FMT = ('%(asctime)s.%(msecs)03d %(levelname)s '
+           '%(module)s - %(funcName)s: %(message)s')
 
 
 class Result:
@@ -109,8 +110,8 @@ def get_experiment_configs(
   benchmark_yamls = []
   if args.benchmark_yaml:
     logger.info(
-        f'A benchmark yaml file ({args.benchmark_yaml}) is provided. '
-        f'Will use it and ignore the files in {args.benchmarks_directory}.')
+        'A benchmark yaml file %s is provided. Will use it and ignore '
+        'the files in %s.', args.benchmark_yaml, args.benchmarks_directory)
     benchmark_yamls = [args.benchmark_yaml]
   else:
     if args.generate_benchmarks:
@@ -370,8 +371,8 @@ def main():
   experiment_configs = get_experiment_configs(args)
   experiment_results = []
 
-  logger.info(f'Running %s experiment(s) in parallels of %s.',
-              len(experiment_configs), str(NUM_EXP))
+  logger.info('Running %d experiment(s) in parallels of %d.',
+              len(experiment_configs), NUM_EXP)
   if NUM_EXP == 1:
     for config in experiment_configs:
       result = run_experiments(*config)
diff --git a/run_one_experiment.py b/run_one_experiment.py
index 5a4bd13914..24535449c3 100644
--- a/run_one_experiment.py
+++ b/run_one_experiment.py
@@ -23,7 +23,6 @@
 
 from data_prep import project_targets
 from data_prep.project_context.context_introspector import ContextRetriever
-from experiment import benchmark as benchmarklib
 from experiment import builder_runner as builder_runner_lib
 from experiment import evaluator as exp_evaluator
 from experiment import oss_fuzz_checkout
@@ -87,8 +86,8 @@ def generate_targets(benchmark: Benchmark,
                      builder: prompt_builder.PromptBuilder,
                      debug: bool = DEBUG) -> list[str]:
   """Generates fuzz target with LLM."""
-  logger.info(f'Generating targets for {benchmark.project} '
-              f'{benchmark.function_signature} using {model.name}..')
+  logger.info('Generating targets for %s %s using %s..', benchmark.project,
+              benchmark.function_signature, model.name)
   model.query_llm(prompt, response_dir=work_dirs.raw_targets, log_output=debug)
 
   _, target_ext = os.path.splitext(benchmark.target_path)
@@ -108,9 +107,9 @@ def generate_targets(benchmark: Benchmark,
   if generated_targets:
     targets_relpath = map(os.path.relpath, generated_targets)
     targets_relpath_str = '\n '.join(targets_relpath)
-    logger.info(f'Generated:\n {targets_relpath_str}')
+    logger.info('Generated:\n %s', targets_relpath_str)
   else:
-    logger.info(f'Failed to generate targets: {generated_targets}')
+    logger.info('Failed to generate targets: %s', generated_targets)
   return generated_targets