diff --git a/Makefile b/Makefile
index e9bd9187..44a8abdc 100644
--- a/Makefile
+++ b/Makefile
@@ -72,7 +72,7 @@ ifeq ($(USE_GIT_VERSION),yes)
 	NEEDED_CXXFLAGS += -DGITVER=\"$(GIT_VERSION)\"
 endif
 
-NEEDED_CXXFLAGS += -MMD -MP -I$(LIB_SRC_DIR) -I$(LIB_CLIENT_SRC_DIR) -I$(LANG_SRC_DIR)
+NEEDED_CXXFLAGS += -MMD -MP -I$(LIB_SRC_DIR) -I$(LIB_CLIENT_SRC_DIR) -I$(LANG_SRC_DIR) -DOPENSSL_SUPPRESS_DEPRECATED
 
 LIB_OBJS        += $(patsubst %.cpp,obj/%.o,$(LIB_SRC))
 LIB_CLIENT_OBJS += $(patsubst %.cpp,obj/%.o,$(LIB_CLIENT_SRC))
diff --git a/build/CMakeLists.txt b/build/CMakeLists.txt
index cf0416cd..82b04497 100644
--- a/build/CMakeLists.txt
+++ b/build/CMakeLists.txt
@@ -210,7 +210,7 @@ if(NOT DEFINED OPENSSL_INCLUDE_DIR)
 endif()
 
 if(OPENSSL_VERSION VERSION_GREATER_EQUAL "3.0.0")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-deprecated-declarations")
+  add_definitions(-DOPENSSL_SUPPRESS_DEPRECATED)
 endif()
 
 if(WITH_UPNP)