diff --git a/code/M3D/M3DWrapper.cpp b/code/M3D/M3DWrapper.cpp
index a610ff2de..291c28d20 100644
--- a/code/M3D/M3DWrapper.cpp
+++ b/code/M3D/M3DWrapper.cpp
@@ -40,7 +40,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ----------------------------------------------------------------------
 */
 
-#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) && !ASSIMP_BUILD_NO_M3D_IMPORTER
+#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) || !ASSIMP_BUILD_NO_M3D_IMPORTER
 
 #include "M3DWrapper.h"
 
diff --git a/code/M3D/M3DWrapper.h b/code/M3D/M3DWrapper.h
index 622ab96c4..ffd9e233e 100644
--- a/code/M3D/M3DWrapper.h
+++ b/code/M3D/M3DWrapper.h
@@ -46,7 +46,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 #ifndef AI_M3DWRAPPER_H_INC
 #define AI_M3DWRAPPER_H_INC
-#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) && !ASSIMP_BUILD_NO_M3D_IMPORTER
+#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) || !ASSIMP_BUILD_NO_M3D_IMPORTER
 
 #include <memory>
 #include <vector>