diff --git a/tools/check_source/check_licenses.py b/tools/check_source/check_licenses.py
index 1efc513b328..dd649414317 100644
--- a/tools/check_source/check_licenses.py
+++ b/tools/check_source/check_licenses.py
@@ -232,6 +232,18 @@ def check_contents(filepath: str, text: str) -> None:
     """
     text_header = text[:EXPECT_SPDX_IN_FIRST_CHARS]
 
+    # Use the license to limit the copyright search,
+    # so code-generation that includes copyright headers don't cause false alarms.
+    license_id = " SPDX-License-Identifier: "
+    license_id_beg = text_header.find(license_id)
+    if license_id_beg == -1:
+        # Allow completely empty files (sometimes `__init__.py`).
+        if not text.rstrip():
+            return
+        # Empty file already accounted for.
+        print("Missing {:s}{:s}".format(license_id, filepath))
+        return
+
     # Check copyright text, reading multiple (potentially multi-line indented) blocks.
     copyright_id = " SPDX-FileCopyrightText: "
 
@@ -242,7 +254,7 @@ def check_contents(filepath: str, text: str) -> None:
             text_header,
             copyright_id,
             copyright_id_step,
-            EXPECT_SPDX_IN_FIRST_CHARS,
+            license_id_beg,
     )) != (-1, -1)):
         if copyright_id_end == -1:
             # Set once.
@@ -262,9 +274,6 @@ def check_contents(filepath: str, text: str) -> None:
     del copyright_id_item, copyright_id_step
 
     if copyright_id_beg == -1:
-        # Allow completely empty files (sometimes `__init__.py`).
-        if not text.rstrip():
-            return
         print("Missing {:s}{:s}".format(copyright_id, filepath))
 
         # Maintain statistics.
@@ -279,13 +288,6 @@ def check_contents(filepath: str, text: str) -> None:
     if blank_lines > 0:
         print("SPDX \"{:s}\" not on first line: {:s}".format(copyright_id, filepath))
 
-    license_id = " SPDX-License-Identifier: "
-    license_id_beg = text_header.find(license_id, copyright_id_end)
-    if license_id_beg == -1:
-        # Empty file already accounted for.
-        print("Missing {:s}{:s}".format(license_id, filepath))
-        return
-
     # Leading char.
     leading_char = text_header[txt_prev_bol(text_header, license_id_beg, 0):license_id_beg].strip()
     text_blank_line = text_header[copyright_id_end:license_id_beg]