diff --git a/crates/sesam-vitale/src/cartevitale.rs b/crates/sesam-vitale/src/cartevitale.rs
index 3c0ba22..d259f90 100644
--- a/crates/sesam-vitale/src/cartevitale.rs
+++ b/crates/sesam-vitale/src/cartevitale.rs
@@ -168,7 +168,9 @@ pub fn LireDroitsVitale(
     let groups = decode_ssv_memory(hex_values, hex_values.len());
 
     unsafe {
-        libc::free(buffer);
+        if !buffer.is_null() {
+            libc::free(buffer); // ??? si liberer avant decode_ssv_memory alors hex_values n'est plus correct ???
+        }
     }
 
     decode_carte_vitale(groups)