diff --git a/os/common/startup/ARMCAx-TZ/compilers/GCC/ld/rules.ld b/os/common/startup/ARMCAx-TZ/compilers/GCC/ld/rules.ld
index ac4e969bd..d9e72dcbd 100644
--- a/os/common/startup/ARMCAx-TZ/compilers/GCC/ld/rules.ld
+++ b/os/common/startup/ARMCAx-TZ/compilers/GCC/ld/rules.ld
@@ -14,7 +14,7 @@
     limitations under the License.
 */
 
-__stacks_total_size__	    = __und_stack_size__ + __abt_stack_size__ + __fiq_stack_size__ + __irq_stack_size__ + __svc_stack_size__ + __sys_stack_size__;
+__stacks_total_size__	    = __und_stack_size__ + __abt_stack_size__ + __fiq_stack_size__ + __irq_stack_size__ + __svc_stack_size__ +  __mon_stack_size__ + __sys_stack_size__;
 
 __ram0_start__          = ORIGIN(ram0);
 __ram0_size__           = LENGTH(ram0);
diff --git a/os/common/startup/ARMCAx-TZ/compilers/GCC/rules.mk b/os/common/startup/ARMCAx-TZ/compilers/GCC/rules.mk
index 0b98a5334..1be8cfa36 100644
--- a/os/common/startup/ARMCAx-TZ/compilers/GCC/rules.mk
+++ b/os/common/startup/ARMCAx-TZ/compilers/GCC/rules.mk
@@ -69,6 +69,13 @@ else
   LDOPT := $(LDOPT),--defsym=__sys_stack_size__=$(USE_SYSTEM_STACKSIZE)
 endif
 
+# Monitor stack size
+ifeq ($(USE_MONITOR_STACKSIZE),)
+  LDOPT := $(LDOPT),--defsym=__mon_stack_size__=0x64
+else
+  LDOPT := $(LDOPT),--defsym=__mon_stack_size__=$(USE_MONITOR_STACKSIZE)
+endif
+
 # Output directory and files
 ifeq ($(BUILDDIR),)
   BUILDDIR = build