diff --git a/kernel/x86_64/zgemv_t_4.c b/kernel/x86_64/zgemv_t_4.c
index 20ccf06f7..f5e5572f9 100644
--- a/kernel/x86_64/zgemv_t_4.c
+++ b/kernel/x86_64/zgemv_t_4.c
@@ -313,7 +313,7 @@ int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT alpha_r, FLOAT alpha_i,
 
 			for( i = 0; i < n1 ; i++)
 			{
-				memset(ybuffer,0,64);
+				memset(ybuffer,0,sizeoff(ybuffer));
 				zgemv_kernel_4x4(NB,ap,xbuffer,ybuffer,alpha);
 				ap[0] += lda4;
 				ap[1] += lda4;
@@ -338,7 +338,7 @@ int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT alpha_r, FLOAT alpha_i,
 
 			for( i = 0; i < n2 ; i++)
 			{
-				memset(ybuffer,0,64);
+				memset(ybuffer,0,sizeof(ybuffer));
 				zgemv_kernel_4x1(NB,a_ptr,xbuffer,ybuffer,alpha);
 				a_ptr += lda;
 				y_ptr[0] += ybuffer[0];
diff --git a/kernel/zarch/zgemv_t_4.c b/kernel/zarch/zgemv_t_4.c
index ba992b767..94a056cab 100644
--- a/kernel/zarch/zgemv_t_4.c
+++ b/kernel/zarch/zgemv_t_4.c
@@ -518,7 +518,7 @@ int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT alpha_r, FLOAT alpha_i,
 
             for( i = 0; i < n1 ; i++)
             {
-                memset(ybuffer,0,64);
+                memset(ybuffer,0,sizeof(ybuffer));
                 zgemv_kernel_4x4(NB,ap,xbuffer,ybuffer,alpha);
                 ap[0] += lda4;
                 ap[1] += lda4;
@@ -543,7 +543,7 @@ int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT alpha_r, FLOAT alpha_i,
 
             for( i = 0; i < n2 ; i++)
             {
-                memset(ybuffer,0,64);
+                memset(ybuffer,0,sizeof(ybuffer));
                 zgemv_kernel_4x1(NB,a_ptr,xbuffer,ybuffer,alpha);
                 a_ptr += lda;
                 y_ptr[0] += ybuffer[0];