diff --git a/arch/arm/src/common/arm_allocateheap.c b/arch/arm/src/common/arm_allocateheap.c
index 4d571fc3a0..ef28edc828 100644
--- a/arch/arm/src/common/arm_allocateheap.c
+++ b/arch/arm/src/common/arm_allocateheap.c
@@ -131,8 +131,14 @@ void weak_function up_allocate_heap(void **heap_start, size_t *heap_size)
 
   board_autoled_on(LED_HEAPALLOCATE);
   *heap_start = (void *)g_idle_topstack;
+
+#ifdef CONFIG_ARCH_PGPOOL_PBASE
+  *heap_size  = CONFIG_ARCH_PGPOOL_PBASE - g_idle_topstack;
+#else
   *heap_size  = CONFIG_RAM_END - g_idle_topstack;
 #endif
+
+#endif
 }
 
 /****************************************************************************