diff --git a/test/fko-wrapper/fko_wrapper.c b/test/fko-wrapper/fko_wrapper.c
index 380410a7..4378051c 100644
--- a/test/fko-wrapper/fko_wrapper.c
+++ b/test/fko-wrapper/fko_wrapper.c
@@ -18,10 +18,16 @@ static void display_ctx(fko_ctx_t ctx);
 static void test_loop(int destroy_ctx_flag);
 
 int main(void) {
+    int i;
 
     test_loop(NO_CTX_DESTROY);
     test_loop(CTX_DESTROY);
 
+    /* call fko_errstr() across valid and invalid values
+    */
+    for (i=-5; i < FKO_LAST_ERROR+5; i++)
+        printf("libfko error (%d): %s\n", i, fko_errstr(i));
+
     return 0;
 }