diff --git a/lib/evse_security/crypto/openssl/openssl_supplier.cpp b/lib/evse_security/crypto/openssl/openssl_supplier.cpp
index a5d0d0e..515ec6d 100644
--- a/lib/evse_security/crypto/openssl/openssl_supplier.cpp
+++ b/lib/evse_security/crypto/openssl/openssl_supplier.cpp
@@ -8,6 +8,7 @@
 #include <everest/logging.hpp>
 
 #include <chrono>
+#include <cstring>
 
 #include <openssl/bio.h>
 #include <openssl/err.h>