diff --git a/spa/include/spa/utils/json.h b/spa/include/spa/utils/json.h
index de849b0c4..7da964398 100644
--- a/spa/include/spa/utils/json.h
+++ b/spa/include/spa/utils/json.h
@@ -372,7 +372,7 @@ static inline int spa_json_parse_stringn(const char *val, int len, char *result,
 						    v < 0xdc00 || v > 0xdfff)
 							continue;
 						p += 6;
-						cp = 0x010000 | ((cp & 0x3ff) << 10) | (v & 0x3ff);
+						cp = 0x010000 + (((cp & 0x3ff) << 10) | (v & 0x3ff));
 					} else if (cp >= 0xdc00 && cp <= 0xdfff)
 						continue;