diff --git a/java/Makefile b/java/Makefile
index a14c951..fbbe101 100644
--- a/java/Makefile
+++ b/java/Makefile
@@ -9,7 +9,7 @@ else
   CFLAGS+=-z noexecstack
   LDFLAGS+=-lrt
 endif
-CFLAGS+= -shared $(JAVA_INC) $(JAVA_INC)/linux -I ../include -I ../../xbyak -I ../../cybozulib/include -Wno-strict-aliasing
+CFLAGS+=$(JAVA_INC) $(JAVA_INC)/linux -I ../include -I ../../xbyak -I ../../cybozulib/include -Wno-strict-aliasing
 MCL_LIB=../lib/libmcl.a
 
 PACKAGE_NAME=com.herumi.mcl
diff --git a/readme.md b/readme.md
index e77f3e1..210a4bc 100644
--- a/readme.md
+++ b/readme.md
@@ -30,6 +30,11 @@ To make sample programs, run
 make sample
 ```
 
+If clang is not installed, then
+```
+make USE_LLVM=0
+```
+
 ## Build for 32-bit Linux
 Build openssl and gmp for 32-bit mode and install <lib32>
 ```