diff --git a/inc/pbuf.h b/inc/pbuf.h
index 423d1d9..07abb5b 100644
--- a/inc/pbuf.h
+++ b/inc/pbuf.h
@@ -53,13 +53,13 @@
 
 
 #define PBUF_DECLARE_POOL(pool_name, pbuf_count, pbuf_size) \
-static uint8_t pool_name##_payload_memory[(pbuf_count) * (pbuf_size)] __attribute__((aligned(4))); \
+static uint8_t pool_name##_payload_memory[(pbuf_count) * (((pbuf_size) + 3) & ~3)] __attribute__((aligned(4))); \
 static pbuf_t pool_name##_memory[pbuf_count]; \
 pbuf_pool_t pool_name
 
 
 #define STATIC_PBUF_DECLARE_POOL(pool_name, pbuf_count, pbuf_size) \
-static uint8_t pool_name##_payload_memory[(pbuf_count) * (pbuf_size)] __attribute__((aligned(4))); \
+static uint8_t pool_name##_payload_memory[(pbuf_count) * (((pbuf_size) + 3) & ~3)] __attribute__((aligned(4))); \
 static pbuf_t pool_name##_memory[pbuf_count]; \
 static pbuf_pool_t pool_name
 
diff --git a/src/pbuf.c b/src/pbuf.c
index 5fb380e..193ad01 100644
--- a/src/pbuf.c
+++ b/src/pbuf.c
@@ -8,6 +8,8 @@
 	assert(pbuf_memory);
 	assert(pbuf_payload_memory);
 
+	pbuf_payload_capacity = (pbuf_payload_capacity + 3) & ~3;
+
 	pool->pbuf_memory = (pbuf_t*)pbuf_memory;
 	pool->pbuf_count = pbuf_count;