diff --git a/big_tests/rebar.config b/big_tests/rebar.config
index d43240b20c1..df7f1923be4 100644
--- a/big_tests/rebar.config
+++ b/big_tests/rebar.config
@@ -15,7 +15,7 @@
         {proper, "1.4.0"},
         {gun, "2.0.0-rc.2"},
         {fusco, "0.1.1"},
-        {escalus, "4.2.5"},
+        {escalus, "4.2.6-rc1"},
         {cowboy, "2.9.0"},
         {csv, "3.0.3", {pkg, csve}},
         {amqp_client, "3.9.5"},
diff --git a/big_tests/rebar.lock b/big_tests/rebar.lock
index d4c244c477c..8413a950869 100644
--- a/big_tests/rebar.lock
+++ b/big_tests/rebar.lock
@@ -8,7 +8,7 @@
   {pkg,<<"credentials_obfuscation">>,<<"2.4.0">>},
   2},
  {<<"csv">>,{pkg,<<"csve">>,<<"3.0.3">>},0},
- {<<"escalus">>,{pkg,<<"escalus">>,<<"4.2.5">>},0},
+ {<<"escalus">>,{pkg,<<"escalus">>,<<"4.2.6-rc1">>},0},
  {<<"esip">>,{pkg,<<"esip">>,<<"1.0.43">>},0},
  {<<"exml">>,{pkg,<<"hexml">>,<<"3.0.5">>},1},
  {<<"fast_pbkdf2">>,{pkg,<<"fast_pbkdf2">>,<<"1.0.1">>},2},
@@ -41,7 +41,7 @@
  {<<"cowlib">>, <<"0B9FF9C346629256C42EBE1EEB769A83C6CB771A6EE5960BD110AB0B9B872063">>},
  {<<"credentials_obfuscation">>, <<"9FB57683B84899CA3546B384E59AB5D3054A9F334EBA50D74C82CD0AE82DD6CA">>},
  {<<"csv">>, <<"69E7D9B3FDC72016644368762C6A3E6CBFEB85BCCADBF1BD99AB6C827E360E04">>},
- {<<"escalus">>, <<"9828AA2CE6E987D7495EC2DAA57E0AAC8A0DF657F6F7F1C12B9D154F826E5A2C">>},
+ {<<"escalus">>, <<"3E19F38C26418CA6C1EC0110895049BCBB7DDE8329B6E46110BA2A2EC0F6842F">>},
  {<<"esip">>, <<"1CBDC073073F80B9B50E2759F66CA13A353EB4F874BCF92501BD4CD767E34D46">>},
  {<<"exml">>, <<"2A79262A744A9B100A9A27A8E76EADCF146F17653DABA2A88A74C8CF5B06ADF3">>},
  {<<"fast_pbkdf2">>, <<"E63454F7FAA6D6E43751DD44EB7C287EB3509DA92CE7F4AE00661AC580A96100">>},
@@ -73,7 +73,7 @@
  {<<"cowlib">>, <<"2B3E9DA0B21C4565751A6D4901C20D1B4CC25CBB7FD50D91D2AB6DD287BC86A9">>},
  {<<"credentials_obfuscation">>, <<"D28A89830E30698B075DE9A4DBE683A20685C6BED1E3B7DF744A0C06E6FF200A">>},
  {<<"csv">>, <<"741D1A55AABADAA3E0FE13051050101A73E90C4570B9F9403A939D9546813521">>},
- {<<"escalus">>, <<"27778DBBEDC8895627F9B5CD0C5B8C330ED2700E01383E10EB776AD6206A7152">>},
+ {<<"escalus">>, <<"C00F31A67AB769E93717FA3DCCC472F6A2A5FA18A333B9A382049836F1428E5F">>},
  {<<"esip">>, <<"B2C758AE52C4588E0399C0B4CE550BFA56551A5A2F828A28389F2614797E4F4B">>},
  {<<"exml">>, <<"426B50FA455C95760BA4F7C75ED76F90A58837742CBE38A86C6A75BEFA383907">>},
  {<<"fast_pbkdf2">>, <<"CF834AB70270C628C8A37E9BFA4D7282AD6FF0C5DE6C8EB6A2F88C09F890857B">>},