diff --git a/Makefile.system b/Makefile.system
index e68fc9d28..76d755ec2 100644
--- a/Makefile.system
+++ b/Makefile.system
@@ -1124,6 +1124,10 @@ ifeq ($(USE_TLS), 1)
 CCOMMON_OPT += -DUSE_TLS
 endif
 
+ifeq ($(BUILD_HALF), 1)
+CCOMMON_OPT += -DBUILD_HALF
+endif
+
 CCOMMON_OPT += -DVERSION=\"$(VERSION)\"
 
 ifndef SYMBOLPREFIX
diff --git a/common_param.h b/common_param.h
index 19a34fa3d..bf0609427 100644
--- a/common_param.h
+++ b/common_param.h
@@ -47,7 +47,7 @@ typedef struct {
   int dtb_entries;
   int offsetA, offsetB, align;
 
-#if 1
+#ifdef BUILD_HALF
   int shgemm_p, shgemm_q, shgemm_r;
   int shgemm_unroll_m, shgemm_unroll_n, shgemm_unroll_mn;