"vsnprintf()" is unsupported on Windows CE. The closest match is "_vsnprintf()".
diff --git a/cs.c b/cs.c
index ebd8109..36d5785 100644
--- a/cs.c
+++ b/cs.c
@@ -88,7 +88,11 @@
cs_calloc_t cs_mem_calloc = calloc;
cs_realloc_t cs_mem_realloc = realloc;
cs_free_t cs_mem_free = free;
+#if defined(_WIN32_WCE)
+cs_vsnprintf_t cs_vsnprintf = _vsnprintf;
+#else // !_WIN32_WCE
cs_vsnprintf_t cs_vsnprintf = vsnprintf;
+#endif // _WIN32_WCE
#else
extern void* kern_os_malloc(size_t size);
extern void kern_os_free(void* addr);