diff --git a/CMakeLists.txt b/CMakeLists.txt
index b748d6e..fa24323 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,6 +19,11 @@ SET(CMAKE_AUTOUIC ON)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+if(APPLE)
+    # Compatibility for bundled old Boost headers used by dbcppp.
+    add_definitions(-D_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION)
+endif()
+
 if(APPLE AND EXISTS /usr/local/opt/qt5)
     # Homebrew installs Qt5 (up to at least 5.9.1) in
     # /usr/local/qt5, ensure it can be found by CMake since