diff --git a/test/test_GXspec.cpp b/test/test_GXspec.cpp
index d0d43f3..13278d9 100644
--- a/test/test_GXspec.cpp
+++ b/test/test_GXspec.cpp
@@ -32,6 +32,10 @@
 #include "GTools.hpp"
 
 
+/* __ Constants __________________________________________________________ */
+const std::string rmfname = PACKAGE_SOURCE"/test/data/rmf.fits";
+
+
 /***********************************************************************//**
  * @brief Set parameters and tests
  **************************************************************************/
@@ -259,6 +263,16 @@ void TestGXspec::test_GRmf(void)
         test_try_failure(e);
     }
 
+    // Test filename constructor
+    test_try("GRmf filename constructor");
+    try {
+        GRmf rmf(rmfname);
+        test_try_success();
+    }
+    catch (std::exception &e) {
+        test_try_failure(e);
+    }
+
     // Test energy boundary constructor
     test_try("GRmf energy boundary constructor");
     try {