diff --git a/tests/data/test795 b/tests/data/test795
index 5964cd78db..8590404143 100644
--- a/tests/data/test795
+++ b/tests/data/test795
@@ -64,7 +64,7 @@ User-Agent: curl/%VERSION
 Accept: */*
 
 B001 CAPABILITY
-B002 AUTHENTICATE PLAIN AHYA
+B002 AUTHENTICATE PLAIN %b64[%00v%00]b64%
 B003 LIST "%TESTNUMBER0002" *
 B004 LOGOUT
 </protocol>
diff --git a/tests/data/test849 b/tests/data/test849
index aa5aac70ea..c48f4447fa 100644
--- a/tests/data/test849
+++ b/tests/data/test849
@@ -14,7 +14,7 @@ RFC4616
 <servercmd>
 AUTH PLAIN
 REPLY AUTHENTICATE +
-REPLY dXJzZWwAa3VydAB4aXBqM3BsbXE= A002 NO Not authorized
+REPLY %b64[ursel%00kurt%00xipj3plmq]b64% A002 NO Not authorized
 </servercmd>
 </reply>
 
@@ -42,7 +42,7 @@ IMAP plain auth with alt authorization identity (Not authorized)
 <protocol crlf="yes">
 A001 CAPABILITY
 A002 AUTHENTICATE PLAIN
-dXJzZWwAa3VydAB4aXBqM3BsbXE=
+%b64[ursel%00kurt%00xipj3plmq]b64%
 </protocol>
 </verify>
 </testcase>
diff --git a/tests/data/test893 b/tests/data/test893
index a35b09a566..1ba48a23a1 100644
--- a/tests/data/test893
+++ b/tests/data/test893
@@ -16,7 +16,7 @@ RFC5034
 <servercmd>
 AUTH PLAIN
 REPLY AUTH +
-REPLY dXJzZWwAa3VydAB4aXBqM3BsbXE= -ERR Not authorized
+REPLY %b64[ursel%00kurt%00xipj3plmq]b64% -ERR Not authorized
 </servercmd>
 </reply>
 
@@ -44,7 +44,7 @@ pop3://%HOSTIP:%POP3PORT/%TESTNUMBER -u kurt:xipj3plmq --sasl-authzid ursel
 <protocol crlf="yes">
 CAPA
 AUTH PLAIN
-dXJzZWwAa3VydAB4aXBqM3BsbXE=
+%b64[ursel%00kurt%00xipj3plmq]b64%
 </protocol>
 </verify>
 </testcase>
diff --git a/tests/data/test953 b/tests/data/test953
index 126d9c61bc..d229e46c68 100644
--- a/tests/data/test953
+++ b/tests/data/test953
@@ -15,7 +15,7 @@ RFC4954
 <servercmd>
 AUTH PLAIN
 REPLY AUTH 334 PLAIN supported
-REPLY dXJzZWwAa3VydAB4aXBqM3BsbXE= 235 Authenticated
+REPLY %b64[ursel%00kurt%00xipj3plmq]b64% 235 Authenticated
 </servercmd>
 </reply>
 
@@ -40,7 +40,7 @@ smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-fr
 <protocol crlf="yes">
 EHLO %TESTNUMBER
 AUTH PLAIN
-dXJzZWwAa3VydAB4aXBqM3BsbXE=
+%b64[ursel%00kurt%00xipj3plmq]b64%
 MAIL FROM:%LTsender@example.com%GT
 RCPT TO:%LTrecipient@example.com%GT
 DATA
diff --git a/tests/data/test954 b/tests/data/test954
index ded0e75024..29f85fb105 100644
--- a/tests/data/test954
+++ b/tests/data/test954
@@ -15,7 +15,7 @@ RFC4954
 <servercmd>
 AUTH PLAIN
 REPLY AUTH 334 PLAIN supported
-REPLY dXJzZWwAa3VydAB4aXBqM3BsbXE= 501 Not authorized
+REPLY %b64[ursel%00kurt%00xipj3plmq]b64% 501 Not authorized
 </servercmd>
 </reply>
 
@@ -46,7 +46,7 @@ smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-fr
 <protocol crlf="yes">
 EHLO %TESTNUMBER
 AUTH PLAIN
-dXJzZWwAa3VydAB4aXBqM3BsbXE=
+%b64[ursel%00kurt%00xipj3plmq]b64%
 </protocol>
 </verify>
 </testcase>