diff --git a/examples/helmholtz/crossPoints/ddm3D.cpp b/examples/helmholtz/crossPoints/ddm3D.cpp
index 93818b90bc0df0582a033705d63f91c3d6eebddd..47460893d817a51ee14e2fbe1e601c5780997b5e 100755
--- a/examples/helmholtz/crossPoints/ddm3D.cpp
+++ b/examples/helmholtz/crossPoints/ddm3D.cpp
@@ -493,6 +493,9 @@ namespace D3 {
     else if (benchmark == "salt") {
       // Read the velocity map
       std::ifstream file("../salt.dat", std::ios::binary);
+      if (!file) {
+        throw gmshfem::common::Exception("File not found: ../salt.dat. Maybe you forgot extracting salt.tar.gz?");
+      }
 
       unsigned int Nx = 0, Ny = 0, Nz = 0;
       file.read((char *) &Nx, sizeof(unsigned int));