diff --git a/src/cmake/externalpackages.cmake b/src/cmake/externalpackages.cmake
index b50a923..c3250b9 100644
--- a/src/cmake/externalpackages.cmake
+++ b/src/cmake/externalpackages.cmake
@@ -108,7 +108,7 @@ if (CMAKE_COMPILER_IS_CLANG AND OPENEXR_VERSION VERSION_LESS 2.3)
     # clang C++ >= 11 doesn't like 'register' keyword in old exr headers
     add_compile_options (-Wno-deprecated-register)
 endif ()
-if (MSVC AND NOT LINKSTATIC)
+if (WIN32 AND BUILD_SHARED_LIBS)
     add_definitions (-DOPENEXR_DLL) # Is this needed for new versions?
 endif ()