diff --git a/cf/w32-def-from-dll.pl b/cf/w32-def-from-dll.pl
index e8ce607fc..d7c412a40 100644
--- a/cf/w32-def-from-dll.pl
+++ b/cf/w32-def-from-dll.pl
@@ -141,6 +141,7 @@ sub use_response_file($)
     close RF;
 }
 
+print "; This is a generated file.  Do not modify directly.\n";
 print "EXPORTS\n";
 
 for (@ARGV) {
diff --git a/packages/windows/kfw_shim/comerr32.def b/packages/windows/kfw_shim/comerr32.def
index eb3e2975c..bdd1a03e5 100644
--- a/packages/windows/kfw_shim/comerr32.def
+++ b/packages/windows/kfw_shim/comerr32.def
@@ -1,3 +1,4 @@
+; This is a generated file.  Do not modify directly.
 EXPORTS
 	add_error_table = _add_error_table@4	@1
 	com_err = com_err.com_err	@2
diff --git a/packages/windows/kfw_shim/comerr64.def b/packages/windows/kfw_shim/comerr64.def
index b95afa190..5496038fc 100644
--- a/packages/windows/kfw_shim/comerr64.def
+++ b/packages/windows/kfw_shim/comerr64.def
@@ -1,3 +1,4 @@
+; This is a generated file.  Do not modify directly.
 EXPORTS
 	add_error_table = add_error_table	@1
 	com_err = com_err.com_err	@2
diff --git a/packages/windows/kfw_shim/gssapi32.def b/packages/windows/kfw_shim/gssapi32.def
index 55e4ea521..e76eda0aa 100644
--- a/packages/windows/kfw_shim/gssapi32.def
+++ b/packages/windows/kfw_shim/gssapi32.def
@@ -1,3 +1,4 @@
+; This is a generated file.  Do not modify directly.
 EXPORTS
 	GSS_C_NT_ANONYMOUS = gssapi.GSS_C_NT_ANONYMOUS	@1
 	GSS_C_NT_EXPORT_NAME = gssapi.GSS_C_NT_EXPORT_NAME	@2
diff --git a/packages/windows/kfw_shim/gssapi64.def b/packages/windows/kfw_shim/gssapi64.def
index 6c940f3d8..685e42cb7 100644
--- a/packages/windows/kfw_shim/gssapi64.def
+++ b/packages/windows/kfw_shim/gssapi64.def
@@ -1,3 +1,4 @@
+; This is a generated file.  Do not modify directly.
 EXPORTS
 	GSS_C_NT_ANONYMOUS = gssapi.GSS_C_NT_ANONYMOUS	@1
 	GSS_C_NT_EXPORT_NAME = gssapi.GSS_C_NT_EXPORT_NAME	@2
diff --git a/packages/windows/kfw_shim/krb5_32.def b/packages/windows/kfw_shim/krb5_32.def
index e6d79affc..7178016d5 100644
--- a/packages/windows/kfw_shim/krb5_32.def
+++ b/packages/windows/kfw_shim/krb5_32.def
@@ -1,3 +1,4 @@
+; This is a generated file.  Do not modify directly.
 EXPORTS
 	krb5_address_compare = heimdal._krb5_address_compare@12	@13
 	krb5_address_order = heimdal._krb5_address_order@12	@14
diff --git a/packages/windows/kfw_shim/krb5_64.def b/packages/windows/kfw_shim/krb5_64.def
index 2adfac008..ddb24948a 100644
--- a/packages/windows/kfw_shim/krb5_64.def
+++ b/packages/windows/kfw_shim/krb5_64.def
@@ -1,3 +1,4 @@
+; This is a generated file.  Do not modify directly.
 EXPORTS
 	krb5_address_compare = heimdal.krb5_address_compare	@13
 	krb5_address_order = heimdal.krb5_address_order	@14