diff --git a/esp32_i2s_parallel_dma.h b/esp32_i2s_parallel_dma.h
index d7678bc..03af99c 100644
--- a/esp32_i2s_parallel_dma.h
+++ b/esp32_i2s_parallel_dma.h
@@ -89,7 +89,7 @@ typedef struct {
 } i2s_parallel_state_t;
 
 void i2s_parallel_flip_to_buffer(i2s_port_t port, int bufid);
-bool i2s_parallel_is_previous_buffer_free();
+bool IRAM_ATTR i2s_parallel_is_previous_buffer_free();
 void i2s_parallel_set_previous_buffer_not_free();
 
 // Callback function for when whole length of DMA chain has been sent out.