diff --git a/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.default.hpp b/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.default.hpp
index 38c2f66594..179086c440 100644
--- a/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.default.hpp
+++ b/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.default.hpp
@@ -13,7 +13,7 @@
 #include <opencv2/core/utility.hpp> // parallel_for_
 
 #define FAST_GEMM_STORAGE (1<<20) // 2^20
-#define FAST_GEMM_MAX_STACKBUF (1 << 14)
+#define FAST_GEMM_MAX_STACKBUF (1 << 13)
 
 #define FAST_GEMM_F32_MC 64
 #define FAST_GEMM_F32_NC 240
diff --git a/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.simd.hpp b/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.simd.hpp
index 47f91f2071..09a05068f9 100644
--- a/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.simd.hpp
+++ b/modules/dnn/src/layers/cpu_kernels/fast_gemm_kernels.simd.hpp
@@ -13,7 +13,7 @@
 #include <opencv2/core/utility.hpp> // parallel_for_
 
 #define FAST_GEMM_STORAGE (1<<20) // 2^20
-#define FAST_GEMM_MAX_STACKBUF (1 << 14)
+#define FAST_GEMM_MAX_STACKBUF (1 << 13)
 
 #if CV_AVX
 #define FAST_GEMM_F32_MC 60