diff --git a/foreign/c/primitives/gauche.scm b/foreign/c/primitives/gauche.scm
index 09d5c39..63d9b26 100644
--- a/foreign/c/primitives/gauche.scm
+++ b/foreign/c/primitives/gauche.scm
@@ -201,14 +201,14 @@
                                                  c-function
                                                  (size-of-type return-type)
                                                  arguments)))
-          (display "HERE: ")
+          (display "Calling C function: ")
+          (write c-name)
+          (newline)
+          (display "HERE SCM:")
           (write return-pointer)
           (newline)
-          (display "HERE2: ")
-          (write (pointer-get return-pointer return-type 0))
-          (newline)
-          (when (not (equal? return-type 'void))
-            (pointer-get return-pointer return-type 0)))))))
+          (cond ((not (equal? return-type 'void))
+                 (pointer-get return-pointer return-type 0))))))))
 
 (define-syntax define-c-procedure
   (syntax-rules ()
diff --git a/tests/primitives.scm b/tests/primitives.scm
index e24511d..ec97a55 100644
--- a/tests/primitives.scm
+++ b/tests/primitives.scm
@@ -284,7 +284,11 @@
 (for-each
   (lambda (str)
     (debug str)
-    (assert equal? (string=? (c-utf8->string (string->c-utf8 str)) str) #t))
+    (let ((utf-eight (string->c-utf8 str)))
+      (debug utf-eight)
+      (let ((str1 (c-utf8->string utf-eight)))
+        (debug str1)
+        (assert equal? (string=? str1 str) #t))))
   (list "100" "Hello world" "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"))