diff --git a/driver/others/memory.c b/driver/others/memory.c
index 1af547fb2..a49fb1fa1 100644
--- a/driver/others/memory.c
+++ b/driver/others/memory.c
@@ -87,6 +87,30 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 #endif
 
+/* Memory buffer must fit two matrix subblocks of maximal size */
+#define XSTR(x) STR(x)
+#define STR(x) #x
+#if BUFFER_SIZE < (SGEMM_DEFAULT_P * SGEMM_DEFAULT_Q * 4 * 2) || \
+    BUFFER_SIZE < (SGEMM_DEFAULT_P * SGEMM_DEFAULT_R * 4 * 2) || \
+    BUFFER_SIZE < (SGEMM_DEFAULT_R * SGEMM_DEFAULT_Q * 4 * 2)
+#warning BUFFER_SIZE is too small for P, Q, and R of SGEMM - large calculations may crash !
+#endif
+#if BUFFER_SIZE < (DGEMM_DEFAULT_P * DGEMM_DEFAULT_Q * 8 * 2) || \
+    BUFFER_SIZE < (DGEMM_DEFAULT_P * DGEMM_DEFAULT_R * 8 * 2) || \
+    BUFFER_SIZE < (DGEMM_DEFAULT_R * DGEMM_DEFAULT_Q * 8 * 2)
+#warning BUFFER_SIZE is too small for P, Q, and R of DGEMM - large calculations may crash !
+#endif
+#if BUFFER_SIZE < (CGEMM_DEFAULT_P * CGEMM_DEFAULT_Q * 8 * 2) || \
+    BUFFER_SIZE < (CGEMM_DEFAULT_P * CGEMM_DEFAULT_R * 8 * 2) || \
+    BUFFER_SIZE < (CGEMM_DEFAULT_R * CGEMM_DEFAULT_Q * 8 * 2)
+#warning BUFFER_SIZE is too small for P, Q, and R of CGEMM - large calculations may crash !
+#endif
+#if BUFFER_SIZE < (ZGEMM_DEFAULT_P * ZGEMM_DEFAULT_Q * 16 * 2) || \
+    BUFFER_SIZE < (ZGEMM_DEFAULT_P * ZGEMM_DEFAULT_R * 16 * 2) || \
+    BUFFER_SIZE < (ZGEMM_DEFAULT_R * ZGEMM_DEFAULT_Q * 16 * 2)
+#warning BUFFER_SIZE is too small for P, Q, and R of ZGEMM - large calculations may crash !
+#endif
+
 #if defined(COMPILE_TLS)
 
 #include <errno.h>
@@ -2740,7 +2764,7 @@ void *blas_memory_alloc(int procpos){
 #ifdef DEBUG
   printf("  Position -> %d\n", position);
 #endif
-WMB;
+
   memory[position].used = 1;
 #if (defined(SMP) || defined(USE_LOCKING)) && !defined(USE_OPENMP)
   UNLOCK_COMMAND(&alloc_lock);