diff --git a/libaegis b/libaegis
index 6a33995..79dee09 160000
--- a/libaegis
+++ b/libaegis
@@ -1 +1 @@
-Subproject commit 6a33995c7e5daea3b10006d813e4b2a7aa8009d8
+Subproject commit 79dee09317bc43e5faaae034e4695369e5661bbb
diff --git a/pyaegis/aegis128l.py b/pyaegis/aegis128l.py
index 1383976..5372a5d 100644
--- a/pyaegis/aegis128l.py
+++ b/pyaegis/aegis128l.py
@@ -6,6 +6,9 @@ into user-provided buffers via optional `into=` (and `mac_into=` for detached).
 Error return codes from the C library raise ValueError.
 """
 
+# All modules are generated from aegis128l.py by tools/gen_modules.py!
+# DO NOT EDIT OTHER ALGORITHM FILES MANUALLY!
+
 import errno
 from collections.abc import Buffer
 
diff --git a/pyaegis/aegis128x2.py b/pyaegis/aegis128x2.py
index d72eafe..3aa83ea 100644
--- a/pyaegis/aegis128x2.py
+++ b/pyaegis/aegis128x2.py
@@ -6,6 +6,9 @@ into user-provided buffers via optional `into=` (and `mac_into=` for detached).
 Error return codes from the C library raise ValueError.
 """
 
+# All modules are generated from aegis128x2.py by tools/gen_modules.py!
+# DO NOT EDIT OTHER ALGORITHM FILES MANUALLY!
+
 import errno
 from collections.abc import Buffer
 
diff --git a/pyaegis/aegis128x4.py b/pyaegis/aegis128x4.py
index 01b949b..ef52bf7 100644
--- a/pyaegis/aegis128x4.py
+++ b/pyaegis/aegis128x4.py
@@ -6,6 +6,9 @@ into user-provided buffers via optional `into=` (and `mac_into=` for detached).
 Error return codes from the C library raise ValueError.
 """
 
+# All modules are generated from aegis128x4.py by tools/gen_modules.py!
+# DO NOT EDIT OTHER ALGORITHM FILES MANUALLY!
+
 import errno
 from collections.abc import Buffer
 
diff --git a/pyaegis/aegis256.py b/pyaegis/aegis256.py
index 7813da5..ea7e136 100644
--- a/pyaegis/aegis256.py
+++ b/pyaegis/aegis256.py
@@ -6,6 +6,9 @@ into user-provided buffers via optional `into=` (and `mac_into=` for detached).
 Error return codes from the C library raise ValueError.
 """
 
+# All modules are generated from aegis256.py by tools/gen_modules.py!
+# DO NOT EDIT OTHER ALGORITHM FILES MANUALLY!
+
 import errno
 from collections.abc import Buffer
 
diff --git a/pyaegis/aegis256x2.py b/pyaegis/aegis256x2.py
index 7ab4ba8..8389caf 100644
--- a/pyaegis/aegis256x2.py
+++ b/pyaegis/aegis256x2.py
@@ -6,6 +6,9 @@ into user-provided buffers via optional `into=` (and `mac_into=` for detached).
 Error return codes from the C library raise ValueError.
 """
 
+# All modules are generated from aegis256x2.py by tools/gen_modules.py!
+# DO NOT EDIT OTHER ALGORITHM FILES MANUALLY!
+
 import errno
 from collections.abc import Buffer
 
diff --git a/pyaegis/aegis256x4.py b/pyaegis/aegis256x4.py
index 86f5633..79392e9 100644
--- a/pyaegis/aegis256x4.py
+++ b/pyaegis/aegis256x4.py
@@ -6,6 +6,9 @@ into user-provided buffers via optional `into=` (and `mac_into=` for detached).
 Error return codes from the C library raise ValueError.
 """
 
+# All modules are generated from aegis256x4.py by tools/gen_modules.py!
+# DO NOT EDIT OTHER ALGORITHM FILES MANUALLY!
+
 import errno
 from collections.abc import Buffer
 
diff --git a/pyaegis/aegis_cdef.h b/pyaegis/aegis_cdef.h
index e3cd4f2..9c5b6c4 100644
--- a/pyaegis/aegis_cdef.h
+++ b/pyaegis/aegis_cdef.h
@@ -1,3 +1,5 @@
+/* This file is generated with tools/gen_cdef.py. Do not edit. */
+
 typedef unsigned char uint8_t;
 typedef unsigned long size_t;
 
diff --git a/tools/gen_cdef.py b/tools/gen_cdef.py
index 4df6a03..1373a5a 100644
--- a/tools/gen_cdef.py
+++ b/tools/gen_cdef.py
@@ -99,6 +99,8 @@ def generate_cdef(include_dir: pathlib.Path) -> str:
     """Generate the complete CFFI cdef string from all aegis headers."""
 
     lines = [
+        "/* This file is generated with tools/gen_cdef.py. Do not edit. */",
+        "",
         "typedef unsigned char uint8_t;",
         "typedef unsigned long size_t;",
         "",