diff --git a/firmware/baseband/baseband_dma.cpp b/firmware/baseband/baseband_dma.cpp
index 88bc443e..520365d1 100644
--- a/firmware/baseband/baseband_dma.cpp
+++ b/firmware/baseband/baseband_dma.cpp
@@ -169,10 +169,10 @@ baseband::buffer_t wait_for_rx_buffer() {
 			const size_t free_index = (next_index + transfers_per_buffer - 2) & transfers_mask;
 			return { reinterpret_cast<sample_t*>(lli_loop[free_index].destaddr), transfer_samples };
 		} else {
-			return { nullptr, 0 };
+			return { };
 		}
 	} else {
-		return { nullptr, 0 };
+		return { };
 	}
 }
 
diff --git a/firmware/common/buffer.hpp b/firmware/common/buffer.hpp
index 9df2d9ee..be1846dd 100644
--- a/firmware/common/buffer.hpp
+++ b/firmware/common/buffer.hpp
@@ -32,18 +32,24 @@ struct buffer_t {
 	const uint32_t sampling_rate;
 
 	constexpr buffer_t(
-		T* const p,
-		const size_t count
-	) : p { p },
-		count { count },
+	) : p { nullptr },
+		count { 0 },
 		sampling_rate { 0 }
 	{
 	}
 
+	constexpr buffer_t(
+		const buffer_t<T>& other
+	) : p { other.p },
+		count { other.count },
+		sampling_rate { other.sampling_rate }
+	{
+	}
+
 	constexpr buffer_t(
 		T* const p,
 		const size_t count,
-		const uint32_t sampling_rate
+		const uint32_t sampling_rate = 0
 	) : p { p },
 		count { count },
 		sampling_rate { sampling_rate }