diff --git a/tests/src/random.c b/tests/src/random.c
index e01bd4d..7f3f401 100644
--- a/tests/src/random.c
+++ b/tests/src/random.c
@@ -35,6 +35,8 @@
 #include <test/random.h>
 #include <string.h>
 
+#include <mbedtls/entropy.h>
+
 int mbedtls_test_rnd_std_rand( void *rng_state,
                                unsigned char *output,
                                size_t len )
@@ -91,8 +93,16 @@
     }
 
     if( len - use_len > 0 )
-        return( mbedtls_test_rnd_std_rand( NULL, output + use_len,
-                                           len - use_len ) );
+    {
+        if( info->fallback_f_rng != NULL )
+        {
+            return( info->fallback_f_rng( info->fallback_p_rng,
+                                          output + use_len,
+                                          len - use_len ) );
+        }
+        else
+            return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
+    }
 
     return( 0 );
 }