diff --git a/mm/mm_gran/mm_gran.h b/mm/mm_gran/mm_gran.h
index 3ef67916d3..5840d9682f 100644
--- a/mm/mm_gran/mm_gran.h
+++ b/mm/mm_gran/mm_gran.h
@@ -32,6 +32,7 @@
 #include <arch/types.h>
 #include <nuttx/mm/gran.h>
 #include <nuttx/mutex.h>
+#include <nuttx/spinlock.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -68,6 +69,7 @@ struct gran_s
   uint16_t   ngranules; /* The total number of (aligned) granules in the heap */
 #ifdef CONFIG_GRAN_INTR
   irqstate_t irqstate;  /* For exclusive access to the GAT */
+  spinlock_t lock;
 #else
   mutex_t    lock;       /* For exclusive access to the GAT */
 #endif
diff --git a/mm/mm_gran/mm_grancritical.c b/mm/mm_gran/mm_grancritical.c
index 5a99a89a6d..0b988ecd07 100644
--- a/mm/mm_gran/mm_grancritical.c
+++ b/mm/mm_gran/mm_grancritical.c
@@ -57,7 +57,7 @@
 int gran_enter_critical(FAR struct gran_s *priv)
 {
 #ifdef CONFIG_GRAN_INTR
-  priv->irqstate = enter_critical_section();
+  priv->irqstate = spin_lock_irqsave(&priv->lock);
   return OK;
 #else
   return nxmutex_lock(&priv->lock);
@@ -67,7 +67,7 @@ int gran_enter_critical(FAR struct gran_s *priv)
 void gran_leave_critical(FAR struct gran_s *priv)
 {
 #ifdef CONFIG_GRAN_INTR
-  leave_critical_section(priv->irqstate);
+  spin_unlock_irqrestore(&priv->lock, priv->irqstate);
 #else
   nxmutex_unlock(&priv->lock);
 #endif