diff --git a/lib/curl_sasl.c b/lib/curl_sasl.c
index 78ad298f20..66639cbacc 100644
--- a/lib/curl_sasl.c
+++ b/lib/curl_sasl.c
@@ -205,18 +205,23 @@ void Curl_sasl_init(struct SASL *sasl, struct Curl_easy *data,
   sasl->force_ir = FALSE;          /* Respect external option */
 
   if(auth != CURLAUTH_BASIC) {
-    sasl->resetprefs = FALSE;
-    sasl->prefmech = SASL_AUTH_NONE;
+    unsigned short mechs = SASL_AUTH_NONE;
+
+    /* If some usable http authentication options have been set, determine
+       new defaults from them. */
     if(auth & CURLAUTH_BASIC)
-      sasl->prefmech |= SASL_MECH_PLAIN | SASL_MECH_LOGIN;
+      mechs |= SASL_MECH_PLAIN | SASL_MECH_LOGIN;
     if(auth & CURLAUTH_DIGEST)
-      sasl->prefmech |= SASL_MECH_DIGEST_MD5;
+      mechs |= SASL_MECH_DIGEST_MD5;
     if(auth & CURLAUTH_NTLM)
-      sasl->prefmech |= SASL_MECH_NTLM;
+      mechs |= SASL_MECH_NTLM;
     if(auth & CURLAUTH_BEARER)
-      sasl->prefmech |= SASL_MECH_OAUTHBEARER | SASL_MECH_XOAUTH2;
+      mechs |= SASL_MECH_OAUTHBEARER | SASL_MECH_XOAUTH2;
     if(auth & CURLAUTH_GSSAPI)
-      sasl->prefmech |= SASL_MECH_GSSAPI;
+      mechs |= SASL_MECH_GSSAPI;
+
+    if(mechs != SASL_AUTH_NONE)
+      sasl->prefmech = mechs;
   }
 }
 
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index ef6d9db392..5b9e3a9ed2 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -125,7 +125,7 @@ test952 test953 test954 test955 test956 test957 test958 test959 test960 \
 test961 test962 test963 test964 test965 test966 test967 test968 test969 \
 test970 test971 test972 test973 test974 test975 test976 test977 test978 \
 test979 test980 test981 test982 test983 test984 test985 test986 test987 \
-test988 test989 test990 test991 \
+test988 test989 test990 test991 test992 \
 \
 test1000 test1001 test1002 test1003 test1004 test1005 test1006 test1007 \
 test1008 test1009 test1010 test1011 test1012 test1013 test1014 test1015 \
diff --git a/tests/data/test992 b/tests/data/test992
new file mode 100644
index 0000000000..dad0aa51a5
--- /dev/null
+++ b/tests/data/test992
@@ -0,0 +1,52 @@
+<testcase>
+<info>
+<keywords>
+SASL
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<servercmd>
+AUTH OAUTHBEARER XOAUTH2
+REPLY AUTH 334 XOAUTH2 supported
+REPLY dXNlcj11c2VyAWF1dGg9QmVhcmVyIG1GXzkuQjVmLTQuMUpxTQEB 235 Authenticated
+</servercmd>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+smtp
+</server>
+<name>
+SASL verify default mechanisms are reset by login options
+</name>
+<stdin>
+mail body
+</stdin>
+<command>
+smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-from sender@example.com -u user --oauth2-bearer mF_9.B5f-4.1JqM --login-options "AUTH=XOAUTH2" -T -
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+EHLO %TESTNUMBER
+AUTH XOAUTH2
+dXNlcj11c2VyAWF1dGg9QmVhcmVyIG1GXzkuQjVmLTQuMUpxTQEB
+MAIL FROM:<sender@example.com>
+RCPT TO:<recipient@example.com>
+DATA
+QUIT
+</protocol>
+<upload>
+mail body
+.
+</upload>
+</verify>
+</testcase>