diff --git a/cr_generate_id.c b/cr_generate_id.c
index 8daa86d..2240c82 100644
--- a/cr_generate_id.c
+++ b/cr_generate_id.c
@@ -121,7 +121,6 @@
 #include "cr_hsm_code.h"
 #endif	// USE_HSM
 // openssl
-#include <openssl/err.h>
 #include <openssl/sha.h>
 #include <openssl/x509.h>
 
diff --git a/cr_generate_id_private.h b/cr_generate_id_private.h
index 065bdb6..aac1133 100644
--- a/cr_generate_id_private.h
+++ b/cr_generate_id_private.h
@@ -126,6 +126,7 @@ extern "C" {
 #include "simplebignum.h"
 #endif // USE_HSM
 
+#include <openssl/err.h>
 #include <openssl/sha.h>
 #include <openssl/ec.h>
 #include "ec_lcl.h"	// EC_KEY (=ec_key_st) 構造体の参照に必要