diff --git a/Makefile b/Makefile
index 04c91d97..b8aa1b35 100644
--- a/Makefile
+++ b/Makefile
@@ -75,7 +75,9 @@ test-nostdlib:
 test-issue: test-picrin-issue test-repl-issue
 
 test-picrin-issue: $(TEST_RUNNER) $(PICRIN_ISSUE_TESTS)
-	$(TEST_RUNNER) $(PICRIN_ISSUE_TESTS)
+	for test in $(PICRIN_ISSUE_TESTS); do \
+	  $(TEST_RUNNER) "$$test"; \
+	done
 
 test-repl-issue: $(REPL_ISSUE_TESTS)
 
diff --git a/t/parameterize.scm b/t/parameterize.scm
index e5454136..44b82f5d 100644
--- a/t/parameterize.scm
+++ b/t/parameterize.scm
@@ -1,4 +1,5 @@
 (import (scheme base)
+        (scheme write)
         (picrin test))
 
 (test-begin)