diff --git a/ctrtool/oschar.c b/ctrtool/oschar.c
index 715eab3..f850ef3 100644
--- a/ctrtool/oschar.c
+++ b/ctrtool/oschar.c
@@ -135,6 +135,7 @@ utf16char_t* strcopy_UTF8toUTF16(const char *src)
 
 	iconv_t cd = iconv_open("UTF-16LE", "UTF-8");
 	iconv(cd, &in, &in_bytes, &out, &out_bytes);
+	iconv_close(cd);
 	return dst;
 }
 
@@ -163,6 +164,7 @@ char* strcopy_UTF16toUTF8(const utf16char_t *src)
 
 	iconv_t cd = iconv_open("UTF-8", "UTF-16LE");
 	iconv(cd, &in, &in_bytes, &out, &out_bytes);
+	iconv_close(cd);
 	return dst;
 }
 #endif