diff --git a/Makefile.rule b/Makefile.rule
index f7ee09f52..7dc6a03f3 100644
--- a/Makefile.rule
+++ b/Makefile.rule
@@ -80,7 +80,7 @@ VERSION = 0.2.16.dev
 # NO_LAPACKE = 1
 
 # If you want to use legacy threaded Level 3 implementation.
-# USE_SIMPLE_THREADED_LEVEL3 = 1
+ USE_SIMPLE_THREADED_LEVEL3 = 1
 
 # If you want to drive whole 64bit region by BLAS. Not all Fortran
 # compiler supports this. It's safe to keep comment it out if you
diff --git a/common_param.h b/common_param.h
index 36d6149ea..8b2085dd6 100644
--- a/common_param.h
+++ b/common_param.h
@@ -1194,6 +1194,8 @@ extern gotoblas_t *gotoblas;
 #define XGEMM_DEFAULT_UNROLL_N 2
 #endif
 
+#define GEMM_THREAD gemm_thread_m
+
 #ifndef GEMM_THREAD
 #define GEMM_THREAD gemm_thread_n
 #endif