diff --git a/arch/blackfin/include/asm/mmu_context.h b/arch/blackfin/include/asm/mmu_context.h
index 3828c70e7a2e..15b16d3e8de8 100644
--- a/arch/blackfin/include/asm/mmu_context.h
+++ b/arch/blackfin/include/asm/mmu_context.h
@@ -30,8 +30,11 @@ extern void *l1sram_alloc_max(void*);
 static inline void free_l1stack(void)
 {
 	nr_l1stack_tasks--;
-	if (nr_l1stack_tasks == 0)
+	if (nr_l1stack_tasks == 0) {
 		l1sram_free(l1_stack_base);
+		l1_stack_base = NULL;
+		l1_stack_len = 0;
+	}
 }
 
 static inline unsigned long