diff --git a/repo2docker/_version.py b/repo2docker/_version.py
index d3b8edb1..065fdc81 100644
--- a/repo2docker/_version.py
+++ b/repo2docker/_version.py
@@ -119,7 +119,7 @@ def run_command(
             return None, None
     else:
         if verbose:
-            print("unable to find command, tried {}".format(commands))
+            print(f"unable to find command, tried {commands}")
         return None, None
     stdout = process.communicate()[0].strip().decode()
     if process.returncode != 0:
@@ -381,7 +381,7 @@ def git_pieces_from_vcs(
             if verbose:
                 fmt = "tag '%s' doesn't start with prefix '%s'"
                 print(fmt % (full_tag, tag_prefix))
-            pieces["error"] = "tag '%s' doesn't start with prefix '%s'" % (
+            pieces["error"] = "tag '{}' doesn't start with prefix '{}'".format(
                 full_tag,
                 tag_prefix,
             )
diff --git a/versioneer.py b/versioneer.py
index 10909eb4..5d28b0d6 100644
--- a/versioneer.py
+++ b/versioneer.py
@@ -502,7 +502,7 @@ def run_command(
             return None, None
     else:
         if verbose:
-            print("unable to find command, tried {}".format(commands))
+            print(f"unable to find command, tried {commands}")
         return None, None
     stdout = process.communicate()[0].strip().decode()
     if process.returncode != 0:
@@ -1418,7 +1418,7 @@ def git_pieces_from_vcs(
             if verbose:
                 fmt = "tag '%s' doesn't start with prefix '%s'"
                 print(fmt % (full_tag, tag_prefix))
-            pieces["error"] = "tag '%s' doesn't start with prefix '%s'" % (
+            pieces["error"] = "tag '{}' doesn't start with prefix '{}'".format(
                 full_tag,
                 tag_prefix,
             )
@@ -1867,7 +1867,7 @@ def get_versions(verbose: bool = False) -> Dict[str, Any]:
     try:
         ver = versions_from_file(versionfile_abs)
         if verbose:
-            print("got version from file {} {}".format(versionfile_abs, ver))
+            print(f"got version from file {versionfile_abs} {ver}")
         return ver
     except NotThisMethod:
         pass