diff --git a/src/include/common/base64.h b/src/include/common/base64.h
index 2d88d31c874..b064275bbb4 100644
--- a/src/include/common/base64.h
+++ b/src/include/common/base64.h
@@ -11,8 +11,8 @@
 #define BASE64_H
 
 /* base 64 */
-extern int	pg_b64_encode(const char *src, int len, char *dst, int dstlen);
-extern int	pg_b64_decode(const char *src, int len, char *dst, int dstlen);
+extern pg_nodiscard int pg_b64_encode(const char *src, int len, char *dst, int dstlen);
+extern pg_nodiscard int pg_b64_decode(const char *src, int len, char *dst, int dstlen);
 extern int	pg_b64_enc_len(int srclen);
 extern int	pg_b64_dec_len(int srclen);