diff --git a/CMakeLists.txt b/CMakeLists.txt
index f41a4b5..07a490b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,7 +52,7 @@ include( ConfigureChecks.cmake )
 
 ###### global compiler settings
 
-add_definitions( -DHAVE_CONFIG_H -DOSSL_097 -DTQCA_PLUGIN )
+add_definitions( -DHAVE_CONFIG_H -DTQCA_PLUGIN )
 
 set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${TQT_CXX_FLAGS}" )
 set( CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined" )
diff --git a/tqca-tls.cpp b/tqca-tls.cpp
index df9eff1..e17f649 100644
--- a/tqca-tls.cpp
+++ b/tqca-tls.cpp
@@ -34,6 +34,10 @@
 #include <openssl/err.h>
 #include <openssl/rand.h>
 
+#if OPENSSL_VERSION_NUMBER >= 0x00907000
+#define OSSL_097
+#endif
+
 #ifndef OSSL_097
 #define NO_AES
 #endif