diff -up yubihsm-shell-2.0.0/pkcs11/tests/ecdh_derive_test.c.gcc9 yubihsm-shell-2.0.0/pkcs11/tests/ecdh_derive_test.c
--- yubihsm-shell-2.0.0/pkcs11/tests/ecdh_derive_test.c.gcc9	2019-02-13 14:40:19.972274817 +0100
+++ yubihsm-shell-2.0.0/pkcs11/tests/ecdh_derive_test.c	2019-02-13 14:40:54.957601833 +0100
@@ -365,7 +365,10 @@ static bool test_ecdh_value(const char *
   }
 
   // Compare values
-  unsigned char ecdh1_bytes[ecdh1_len]; // public key in DER
+  unsigned char *ecdh1_bytes = malloc(ecdh1_len); // public key in DER
+  if (ecdh1_bytes == NULL) {
+    return false;
+  }
   if (get_yhvalue(*ecdh1, ecdh1_bytes, ecdh1_len) == 0) {
     fail("Failed to retrieve derived key from Yubi library");
     return false;
@@ -378,6 +381,7 @@ static bool test_ecdh_value(const char *
       break;
     }
   }
+  free(ecdh1_bytes);
   if (!equal) {
     fail("ECDH keys derived with yubi library and with openssl do not have the "
          "same value");
@@ -416,7 +420,11 @@ static bool test_dublicate_ecdh(const ch
     return false;
   }
 
-  unsigned char ecdh1_value[ecdh1_len], ecdh2_value[ecdh2_len];
+  unsigned char *ecdh1_value = malloc(ecdh1_len);
+  unsigned char *ecdh2_value = malloc(ecdh2_len);
+  if (ecdh1_value == NULL || ecdh2_value == NULL) {
+    return false;
+  }
   if (get_yhvalue(*ecdh2, ecdh1_value, ecdh1_len) == 0) {
     return false;
   }