diff --git a/sharkd_session.c b/sharkd_session.c
index ffb9b60464..c9aa258407 100644
--- a/sharkd_session.c
+++ b/sharkd_session.c
@@ -388,8 +388,8 @@ json_prep(char* buf, const jsmntok_t* tokens, int count)
         {"follow",     "filter",     2, JSMN_STRING,       SHARKD_JSON_STRING,   MANDATORY},
         {"frame",      "frame",      2, JSMN_PRIMITIVE,    SHARKD_JSON_UINTEGER, MANDATORY},
         {"frame",      "proto",      2, JSMN_PRIMITIVE,    SHARKD_JSON_BOOLEAN,  OPTIONAL},
-        {"frame",      "ref_frame",  2, JSMN_PRIMITIVE,    SHARKD_JSON_BOOLEAN,  OPTIONAL},
-        {"frame",      "prev_frame", 2, JSMN_PRIMITIVE,    SHARKD_JSON_BOOLEAN,  OPTIONAL},
+        {"frame",      "ref_frame",  2, JSMN_PRIMITIVE,    SHARKD_JSON_UINTEGER, OPTIONAL},
+        {"frame",      "prev_frame", 2, JSMN_PRIMITIVE,    SHARKD_JSON_UINTEGER, OPTIONAL},
         {"frame",      "columns",    2, JSMN_PRIMITIVE,    SHARKD_JSON_BOOLEAN,  OPTIONAL},
         {"frame",      "color",      2, JSMN_PRIMITIVE,    SHARKD_JSON_BOOLEAN,  OPTIONAL},
         {"frame",      "bytes",      2, JSMN_PRIMITIVE,    SHARKD_JSON_BOOLEAN,  OPTIONAL},