diff --git a/src/cpp/security/authentication/PKIDH.cpp b/src/cpp/security/authentication/PKIDH.cpp
index 2dfcbf32d05..567a33ad8cd 100644
--- a/src/cpp/security/authentication/PKIDH.cpp
+++ b/src/cpp/security/authentication/PKIDH.cpp
@@ -16,6 +16,10 @@
  * @file PKIDH.cpp
  */
 
+// TODO This isn't a proper fix for compatibility with OpenSSL 3.0, but
+// suppresses the warnings until true OpenSSL 3.0 APIs can be used.
+#define OPENSSL_API_COMPAT 10101
+
 #include <security/authentication/PKIDH.h>
 #include <security/authentication/PKIIdentityHandle.h>
 #include <fastdds/rtps/security/logging/Logging.h>