diff --git a/src/arch/i386/core/gdbidt.S b/src/arch/i386/core/gdbidt.S
index 78945c62c..5af0e3d2d 100644
--- a/src/arch/i386/core/gdbidt.S
+++ b/src/arch/i386/core/gdbidt.S
@@ -1,3 +1,5 @@
+FILE_SECBOOT ( FORBIDDEN );
+
 /*
  * Interrupt handlers for GDB stub
  */
diff --git a/src/arch/i386/include/bits/gdbmach.h b/src/arch/i386/include/bits/gdbmach.h
index 52cce7833..b338d471d 100644
--- a/src/arch/i386/include/bits/gdbmach.h
+++ b/src/arch/i386/include/bits/gdbmach.h
@@ -10,6 +10,8 @@
  *
  */
 
+FILE_SECBOOT ( FORBIDDEN );
+
 #include <stdint.h>
 
 typedef unsigned long gdbreg_t;
diff --git a/src/arch/x86/core/gdbmach.c b/src/arch/x86/core/gdbmach.c
index d4d187e35..cb606f67b 100644
--- a/src/arch/x86/core/gdbmach.c
+++ b/src/arch/x86/core/gdbmach.c
@@ -23,6 +23,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 #include <stddef.h>
 #include <stdio.h>
diff --git a/src/arch/x86_64/core/gdbidt.S b/src/arch/x86_64/core/gdbidt.S
index 477492b47..b19b66406 100644
--- a/src/arch/x86_64/core/gdbidt.S
+++ b/src/arch/x86_64/core/gdbidt.S
@@ -22,6 +22,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 /** @file
  *
diff --git a/src/arch/x86_64/include/bits/gdbmach.h b/src/arch/x86_64/include/bits/gdbmach.h
index 367405fd6..486b0d08c 100644
--- a/src/arch/x86_64/include/bits/gdbmach.h
+++ b/src/arch/x86_64/include/bits/gdbmach.h
@@ -10,6 +10,8 @@
  *
  */
 
+FILE_SECBOOT ( FORBIDDEN );
+
 #include <stdint.h>
 
 typedef unsigned long gdbreg_t;
diff --git a/src/core/gdbserial.c b/src/core/gdbserial.c
index 61add5d47..bfdb9dcec 100644
--- a/src/core/gdbserial.c
+++ b/src/core/gdbserial.c
@@ -22,6 +22,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 #include <stddef.h>
 #include <stdio.h>
diff --git a/src/core/gdbstub.c b/src/core/gdbstub.c
index d668f454a..72b1105de 100644
--- a/src/core/gdbstub.c
+++ b/src/core/gdbstub.c
@@ -22,6 +22,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 /**
  * @file
diff --git a/src/core/gdbudp.c b/src/core/gdbudp.c
index e4613d137..5aea6fadf 100644
--- a/src/core/gdbudp.c
+++ b/src/core/gdbudp.c
@@ -22,6 +22,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 #include <stdio.h>
 #include <string.h>
diff --git a/src/hci/commands/gdbstub_cmd.c b/src/hci/commands/gdbstub_cmd.c
index ba5edde3a..c3551db2d 100644
--- a/src/hci/commands/gdbstub_cmd.c
+++ b/src/hci/commands/gdbstub_cmd.c
@@ -22,6 +22,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 #include <stdio.h>
 #include <errno.h>
diff --git a/src/include/bits/gdbmach.h b/src/include/bits/gdbmach.h
index 7e349856f..0bc49430a 100644
--- a/src/include/bits/gdbmach.h
+++ b/src/include/bits/gdbmach.h
@@ -10,6 +10,8 @@
  *
  */
 
+FILE_SECBOOT ( FORBIDDEN );
+
 #include <stdint.h>
 
 typedef unsigned long gdbreg_t;
diff --git a/src/include/ipxe/gdbserial.h b/src/include/ipxe/gdbserial.h
index 62cc16014..4667c760d 100644
--- a/src/include/ipxe/gdbserial.h
+++ b/src/include/ipxe/gdbserial.h
@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 struct gdb_transport;
 
diff --git a/src/include/ipxe/gdbstub.h b/src/include/ipxe/gdbstub.h
index 2240cca42..ef7bb6dd9 100644
--- a/src/include/ipxe/gdbstub.h
+++ b/src/include/ipxe/gdbstub.h
@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 #include <stdint.h>
 #include <ipxe/tables.h>
diff --git a/src/include/ipxe/gdbudp.h b/src/include/ipxe/gdbudp.h
index a1c091522..5790520c9 100644
--- a/src/include/ipxe/gdbudp.h
+++ b/src/include/ipxe/gdbudp.h
@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( FORBIDDEN );
 
 struct sockaddr_in;
 struct gdb_transport;