diff --git a/tests/unit/tests_high_five_easy.cpp b/tests/unit/tests_high_five_easy.cpp
index 067b035e3..aa30b4e96 100644
--- a/tests/unit/tests_high_five_easy.cpp
+++ b/tests/unit/tests_high_five_easy.cpp
@@ -30,6 +30,9 @@
 #include <Eigen/Dense>
 #endif
 
+#ifdef HIGHFIVE_TEST_OPENCV
+#define H5_USE_OPENCV
+#endif
 
 #include <highfive/H5Easy.hpp>