diff --git a/tests/scripts/generate_test_code.py b/tests/scripts/generate_test_code.py
index 6d65986c88..938f24cf4f 100755
--- a/tests/scripts/generate_test_code.py
+++ b/tests/scripts/generate_test_code.py
@@ -126,33 +126,39 @@ code that is generated or read from helpers and platform files.
 This script replaces following fields in the template and generates
 the test source file:
 
-__MBEDTLS_TEST_TEMPLATE__TEST_COMMON_HELPERS    <-- All common code from helpers.function
-                                                    is substituted here.
-__MBEDTLS_TEST_TEMPLATE__FUNCTIONS_CODE         <-- Test functions are substituted here
-                                                    from the input test_suit_xyz.function
-                                                    file. C preprocessor checks are generated
-                                                    for the build dependencies specified
-                                                    in the input file. This script also
-                                                    generates wrappers for the test
-                                                    functions with code to expand the
-                                                    string parameters read from the data
-                                                    file.
-__MBEDTLS_TEST_TEMPLATE__EXPRESSION_CODE        <-- This script enumerates the
-                                                    expressions in the .data file and
-                                                    generates code to handle enumerated
-                                                    expression Ids and return the values.
-__MBEDTLS_TEST_TEMPLATE__DEP_CHECK_CODE         <-- This script enumerates all
-                                                    build dependencies and generate
-                                                    code to handle enumerated build
-                                                    dependency Id and return status: if
-                                                    the dependency is defined or not.
-__MBEDTLS_TEST_TEMPLATE__DISPATCH_CODE          <-- This script enumerates the functions
-                                                    specified in the input test data file
-                                                    and generates the initializer for the
-                                                    function table in the template
-                                                    file.
-__MBEDTLS_TEST_TEMPLATE__PLATFORM_CODE          <-- Platform specific setup and test
-                                                    dispatch code.
+__MBEDTLS_TEST_TEMPLATE__TEST_COMMON_HELPERS
+            All common code from helpers.function
+            is substituted here.
+__MBEDTLS_TEST_TEMPLATE__FUNCTIONS_CODE
+            Test functions are substituted here
+            from the input test_suit_xyz.function
+            file. C preprocessor checks are generated
+            for the build dependencies specified
+            in the input file. This script also
+            generates wrappers for the test
+            functions with code to expand the
+            string parameters read from the data
+            file.
+__MBEDTLS_TEST_TEMPLATE__EXPRESSION_CODE
+            This script enumerates the
+            expressions in the .data file and
+            generates code to handle enumerated
+            expression Ids and return the values.
+__MBEDTLS_TEST_TEMPLATE__DEP_CHECK_CODE
+            This script enumerates all
+            build dependencies and generate
+            code to handle enumerated build
+            dependency Id and return status: if
+            the dependency is defined or not.
+__MBEDTLS_TEST_TEMPLATE__DISPATCH_CODE
+            This script enumerates the functions
+            specified in the input test data file
+            and generates the initializer for the
+            function table in the template
+            file.
+__MBEDTLS_TEST_TEMPLATE__PLATFORM_CODE
+            Platform specific setup and test
+            dispatch code.
 
 """
 
@@ -985,10 +991,7 @@ def write_test_source_file(template_file, c_file, snippets):
     braced = "(?P<braced>(?!))"
     # If not already matched, a "__MBEDTLS_TEST_TEMPLATE__" prefix is invalid.
     invalid = "(?P<invalid>__MBEDTLS_TEST_TEMPLATE__)"
-    placeholder_pattern = re.compile(escaped \
-            + "|" + named \
-            + "|" + braced \
-            + "|" + invalid)
+    placeholder_pattern = re.compile("|".join([escaped, named, braced, invalid]))
 
     with open(template_file, 'r') as template_f, open(c_file, 'w') as c_f:
         for line_no, line in enumerate(template_f.readlines(), 1):