diff --git a/src/ocrmypdf/_exec/ghostscript.py b/src/ocrmypdf/_exec/ghostscript.py
index 0ccadc45..111ccf42 100644
--- a/src/ocrmypdf/_exec/ghostscript.py
+++ b/src/ocrmypdf/_exec/ghostscript.py
@@ -45,7 +45,7 @@ For details see:
 """
 
 # Most reliable what to get the bitness of Python interpreter, according to Python docs
-_is_64bit = sys.maxsize > 2 ** 32
+_is_64bit = sys.maxsize > 2**32
 
 _gswin = None
 if os.name == 'nt':
@@ -115,7 +115,7 @@ def rasterize_pdf(
         + [
             '-o',
             '-',
-            '-sstdout=%stderr',
+            '-sstdout=%stderr',  # Literal %s, not string interpolation
             '-dAutoRotatePages=/None',  # Probably has no effect on raster
             '-f',
             fspath(input_file),
@@ -251,7 +251,7 @@ def generate_pdfa(
             "-dPDFACompatibilityPolicy=1",
             "-o",
             "-",
-            "-sstdout=%stderr",
+            "-sstdout=%stderr",  # Literal %s, not string interpolation
         ]
     )
     args_gs.extend(fspath(s) for s in pdf_pages)  # Stringify Path objs
diff --git a/src/ocrmypdf/_exec/tesseract.py b/src/ocrmypdf/_exec/tesseract.py
index 04c556e4..0e032026 100644
--- a/src/ocrmypdf/_exec/tesseract.py
+++ b/src/ocrmypdf/_exec/tesseract.py
@@ -57,7 +57,7 @@ TESSERACT_THRESHOLDING_METHODS: Dict[str, int] = {
 class TesseractLoggerAdapter(logging.LoggerAdapter):
     def process(self, msg, kwargs):
         kwargs['extra'] = self.extra
-        return '[tesseract] %s' % (msg), kwargs
+        return f'[tesseract] {msg}', kwargs
 
 
 TESSERACT_VERSION_PATTERN = r"""
diff --git a/src/ocrmypdf/_jobcontext.py b/src/ocrmypdf/_jobcontext.py
index 2363ccbb..11f04cf2 100644
--- a/src/ocrmypdf/_jobcontext.py
+++ b/src/ocrmypdf/_jobcontext.py
@@ -83,7 +83,7 @@ class PageContext:
         The path will be based in a common temporary folder and have a prefix based
         on the page number.
         """
-        return self.work_folder / ("%06d_%s" % (self.pageno + 1, name))
+        return self.work_folder / f"{(self.pageno + 1):06d}_{name}"
 
     def __getstate__(self):
         state = self.__dict__.copy()