diff --git a/m-buffer.h b/m-buffer.h
index 235d3f9b..961d77db 100644
--- a/m-buffer.h
+++ b/m-buffer.h
@@ -602,6 +602,13 @@ M_C(name, _init)(buffer_t v, size_t size)                               \
     */                                                                  \
     return iP-iC;							\
   }									\
+                                                                        \
+ static inline size_t                                                   \
+ M_C(name, _capacity)(const buffer_t v)                                 \
+ {                                                                      \
+   QUEUEI_MPMC_CONTRACT(v);                                             \
+   return v->size;                                                      \
+ }                                                                      \
 									\
   static inline bool							\
   M_C(name, _empty_p)(buffer_t v)					\
@@ -720,6 +727,12 @@ M_C(name, _init)(buffer_t v, size_t size)                               \
     return w-r;                                                         \
   }                                                                     \
                                                                         \
+ static inline size_t                                                   \
+ M_C(name, _capacity)(const buffer_t v)                                 \
+ {                                                                      \
+   return v->size;                                                      \
+ }                                                                      \
+                                                                        \
   static inline bool							\
   M_C(name, _empty_p)(buffer_t v)					\
   {									\
diff --git a/tests/test-mbuffer.c b/tests/test-mbuffer.c
index b0a7721a..f1c33b7c 100644
--- a/tests/test-mbuffer.c
+++ b/tests/test-mbuffer.c
@@ -72,6 +72,7 @@ static void test_global(void)
   m_thread_t idx_c[MAX_TEST_THREAD];
 
   buffer_uint_init(g_buff, 10);
+  assert (buffer_uint_capacity(g_buff) == 10);
   
   for(int i = 0; i < MAX_TEST_THREAD; i++) {
     m_thread_create (idx_p[i], conso, NULL);
@@ -121,6 +122,7 @@ static void test_stack(void)
 {
   buffer_floats_t buff;
   buffer_floats_init(buff, 100);
+  assert (buffer_floats_capacity(buff) == 100);
   for(unsigned int i = 0; i < 100; i++) {
     float f = i;
     buffer_floats_push(buff, f);
@@ -340,6 +342,8 @@ static void test_queue(size_t n, int cpu_count, unsigned long long ref)
   // Init
   queue_uint_init(g_buff2, 64*2);
   queue_ull_init (g_final2, 64*2);
+  assert (queue_uint_capacity(g_buff2) == 64*2);
+  assert (queue_ull_capacity(g_final2) == 64*2);
 
   // Create thread
   m_thread_t idx_p[64];