diff --git a/infra/build/functions/build_and_run_coverage.py b/infra/build/functions/build_and_run_coverage.py
index 6c085a79b..004403c1f 100755
--- a/infra/build/functions/build_and_run_coverage.py
+++ b/infra/build/functions/build_and_run_coverage.py
@@ -111,7 +111,8 @@ def get_build_steps(  # pylint: disable=too-many-locals, too-many-arguments
   env = build_project.get_env(project.fuzzing_language, build)
   build_steps.append(
       build_project.get_compile_step(project, build, env, config.parallel))
-  download_corpora_steps = build_lib.download_corpora_steps(project.name)
+  download_corpora_steps = build_lib.download_corpora_steps(
+      project.name, test_image_suffix=config.test_image_suffix)
   if not download_corpora_steps:
     logging.info('Skipping code coverage build for %s.', project.name)
     return []
@@ -133,8 +134,8 @@ def get_build_steps(  # pylint: disable=too-many-locals, too-many-arguments
 
   build_steps.append({
       'name':
-          build_project.get_runner_image_name(base_images_project,
-                                              config.test_image_suffix),
+          build_lib.get_runner_image_name(base_images_project,
+                                          config.test_image_suffix),
       'env':
           coverage_env,
       'args': [
diff --git a/infra/build/functions/build_lib.py b/infra/build/functions/build_lib.py
index d10166a10..8c0ff88e3 100644
--- a/infra/build/functions/build_lib.py
+++ b/infra/build/functions/build_lib.py
@@ -30,6 +30,8 @@ from oauth2client.service_account import ServiceAccountCredentials
 import requests
 import yaml
 
+BASE_IMAGES_PROJECT = 'oss-fuzz-base'
+
 BUILD_TIMEOUT = 16 * 60 * 60
 
 # Needed for reading public target.list.* files.
@@ -184,7 +186,7 @@ def get_signed_url(path, method='PUT', content_type=''):
   return f'https://storage.googleapis.com{path}?{urlparse.urlencode(values)}'
 
 
-def download_corpora_steps(project_name):
+def download_corpora_steps(project_name, test_image_suffix):
   """Returns GCB steps for downloading corpora backups for the given project.
   """
   fuzz_targets = _get_targets_list(project_name)
@@ -210,7 +212,7 @@ def download_corpora_steps(project_name):
       download_corpus_args.append('%s %s' % (corpus_archive_path, url))
 
     steps.append({
-        'name': 'gcr.io/oss-fuzz-base/base-runner',
+        'name': get_runner_image_name(BASE_IMAGES_PROJECT, test_image_suffix),
         'entrypoint': 'download_corpus',
         'args': download_corpus_args,
         'volumes': [{
@@ -476,6 +478,15 @@ def get_gcb_url(build_id, cloud_project='oss-fuzz'):
       f'{build_id}?project={cloud_project}')
 
 
+def get_runner_image_name(base_images_project, test_image_suffix):
+  """Returns the runner image that should be used, based on
+  |base_images_project|. Returns the testing image if |test_image_suffix|."""
+  image = f'gcr.io/{base_images_project}/base-runner'
+  if test_image_suffix:
+    image += '-' + test_image_suffix
+  return image
+
+
 def get_build_body(steps,
                    timeout,
                    body_overrides,
diff --git a/infra/build/functions/build_project.py b/infra/build/functions/build_project.py
index bbb7df9e0..a67c13c51 100755
--- a/infra/build/functions/build_project.py
+++ b/infra/build/functions/build_project.py
@@ -313,8 +313,8 @@ def get_build_steps(  # pylint: disable=too-many-locals, too-many-statements, to
           # Test fuzz targets.
           test_step = {
               'name':
-                  get_runner_image_name(base_images_project,
-                                        config.test_image_suffix),
+                  build_lib.get_runner_image_name(base_images_project,
+                                                  config.test_image_suffix),
               'env':
                   env,
               'args': [
@@ -347,8 +347,8 @@ def get_build_steps(  # pylint: disable=too-many-locals, too-many-statements, to
             # Generate targets list.
             {
                 'name':
-                    get_runner_image_name(base_images_project,
-                                          config.test_image_suffix),
+                    build_lib.get_runner_image_name(base_images_project,
+                                                    config.test_image_suffix),
                 'env':
                     env,
                 'args': [
@@ -451,15 +451,6 @@ def get_cleanup_step(project, build):
   }
 
 
-def get_runner_image_name(base_images_project, test_image_suffix):
-  """Returns the runner image that should be used, based on
-  |base_images_project|. Returns the testing image if |test_image_suffix|."""
-  image = f'gcr.io/{base_images_project}/base-runner'
-  if test_image_suffix:
-    image += '-' + test_image_suffix
-  return image
-
-
 # pylint: disable=no-member,too-many-arguments
 def run_build(oss_fuzz_project,
               build_steps,
@@ -523,7 +514,6 @@ def build_script_main(script_description, get_build_steps_func, build_type):
   logging.basicConfig(level=logging.INFO)
 
   image_project = 'oss-fuzz'
-  base_images_project = 'oss-fuzz-base'
 
   credentials = oauth2client.client.GoogleCredentials.get_application_default()
   error = False
@@ -543,7 +533,7 @@ def build_script_main(script_description, get_build_steps_func, build_type):
 
     steps = get_build_steps_func(project_name, project_yaml,
                                  dockerfile_contents, image_project,
-                                 base_images_project, config)
+                                 build_lib.BASE_IMAGES_PROJECT, config)
     if not steps:
       logging.error('No steps. Skipping %s.', project_name)
       error = True