diff --git a/kernel/x86_64/gemm_kernel_4x8_nano.S b/kernel/x86_64/gemm_kernel_4x8_nano.S
index 074562804c..e29520fa1b 100644
--- a/kernel/x86_64/gemm_kernel_4x8_nano.S
+++ b/kernel/x86_64/gemm_kernel_4x8_nano.S
@@ -135,7 +135,7 @@
 #endif
 
 	movq	%rsp, %rbx	# save old stack
-	subq	$128 + LOCAL_BUFFER_SIZE, %rsp
+	subq	$256 + LOCAL_BUFFER_SIZE, %rsp
 	andq	$-4096, %rsp	# align stack
 
 	STACK_TOUCHING
diff --git a/kernel/x86_64/gemm_kernel_8x4_sse.S b/kernel/x86_64/gemm_kernel_8x4_sse.S
index c4ef1f809a..1602c13c50 100644
--- a/kernel/x86_64/gemm_kernel_8x4_sse.S
+++ b/kernel/x86_64/gemm_kernel_8x4_sse.S
@@ -383,7 +383,7 @@
 	EMMS
 
 	movq	%rsp, %rbx	# save old stack
-	subq	$128 + LOCAL_BUFFER_SIZE, %rsp
+	subq	$256 + LOCAL_BUFFER_SIZE, %rsp
 	andq	$-4096, %rsp	# align stack
 
 	STACK_TOUCHING