diff --git a/Sming/custom_heap/heap.c b/Sming/custom_heap/heap.c
index 9fc0a97d21..d1bf76da79 100644
--- a/Sming/custom_heap/heap.c
+++ b/Sming/custom_heap/heap.c
@@ -35,6 +35,8 @@ void* IRAM_ATTR pvPortZalloc(size_t size, const char* file, int line)
     return calloc(1, size);
 }
 
+void* IRAM_ATTR pvPortZallocIram(size_t size, const char* file, int line) __attribute__ ((weak, alias("pvPortZalloc")));
+
 size_t xPortGetFreeHeapSize(void)
 {
     return umm_free_heap_size();