diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index cfc3439b8..5443b61b7 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -72,6 +72,7 @@ set_target_properties(glfw PROPERTIES
 
 if (BUILD_SHARED_LIBS)
     if (WIN32)
+        target_compile_definitions(glfw INTERFACE -DGLFW_DLL)
         # The GLFW DLL needs a special compile-time macro and import library name
         set_target_properties(glfw PROPERTIES PREFIX "" IMPORT_PREFIX "")