diff --git a/nalgebra-sparse/example/spmm.rs b/nalgebra-sparse/example/spmm.rs
index aa4eb473..2be64735 100644
--- a/nalgebra-sparse/example/spmm.rs
+++ b/nalgebra-sparse/example/spmm.rs
@@ -10,19 +10,23 @@ use nalgebra_sparse::io::load_coo_from_matrix_market_file;
 fn main() {
     #[cfg(feature = "io")]
     {
-        let mut file_iter = fs::read_dir("./data").unwrap();
+        let mut file_iter = fs::read_dir("data").unwrap();
         for f in file_iter {
             println!("Benchmark file {:?}", f);
             let f = f.unwrap().path();
-            let sparse_input_matrix = load_coo_from_matrix_market_file::<f64, _>(&f).unwrap();
-            let sparse_input_matrix = CsrMatrix::from(&sparse_input_matrix);
-            let spmm_result = &sparse_input_matrix * &sparse_input_matrix;
-            let now = Instant::now();
-            let spmm_result = &sparse_input_matrix * &sparse_input_matrix;
-            let spmm_time = now.elapsed().as_millis();
-            println!("SGEMM time was {}", spmm_time);
-            let sum: f64 = spmm_result.triplet_iter().map(|(_, _, v)| v).sum();
-            println!("sum of product is {}", sum);
+
+            if f.extension().map_or(false, |ext| ext == "mtx") {
+                println!("Benchmark file {:?}", f);
+                let sparse_input_matrix = load_coo_from_matrix_market_file::<f64, _>(&f).unwrap();
+                let sparse_input_matrix = CsrMatrix::from(&sparse_input_matrix);
+                let spmm_result = &sparse_input_matrix * &sparse_input_matrix;
+                let now = Instant::now();
+                let spmm_result = &sparse_input_matrix * &sparse_input_matrix;
+                let spmm_time = now.elapsed().as_millis();
+                println!("SGEMM time was {}", spmm_time);
+                let sum: f64 = spmm_result.triplet_iter().map(|(_, _, v)| v).sum();
+                println!("sum of product is {}", sum);
+            }
         }
     }
     #[cfg(not(feature = "io"))]