diff --git a/src/api/crypto.cpp b/src/api/crypto.cpp
index a8f62698..d5eabdea 100644
--- a/src/api/crypto.cpp
+++ b/src/api/crypto.cpp
@@ -30,6 +30,7 @@
 
 #include <openssl/bio.h>
 #include <openssl/bn.h>
+#include <openssl/crypto.h>
 #include <openssl/engine.h>
 #include <openssl/err.h>
 #include <openssl/evp.h>
diff --git a/src/main.cpp b/src/main.cpp
index 4a282782..685f21f8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -53,6 +53,7 @@
 #include <tuple>
 
 #include <openssl/opensslv.h>
+#include <openssl/conf.h>
 
 using namespace pipy;