diff --git a/libaegisub/common/charset_conv.cpp b/libaegisub/common/charset_conv.cpp
index 47644eb1c..f19090c15 100644
--- a/libaegisub/common/charset_conv.cpp
+++ b/libaegisub/common/charset_conv.cpp
@@ -420,7 +420,7 @@ size_t IconvWrapper::DstStrLen(const char* str) {
 bool IsConversionSupported(const char *src, const char *dst) {
 	iconv_t cd = iconv_open(dst, src);
 	bool supported = cd != iconv_invalid;
-	iconv_close(cd);
+	if (supported) iconv_close(cd);
 	return supported;
 }