diff --git a/lib/setopt.c b/lib/setopt.c
index 6a4990cce6..ce1321fc80 100644
--- a/lib/setopt.c
+++ b/lib/setopt.c
@@ -155,6 +155,12 @@ static CURLcode setstropt_userpwd(char *option, char **userp, char **passwdp)
 
 static CURLcode protocol2num(const char *str, curl_prot_t *val)
 {
+  /*
+   * We are asked to cherry-pick protocols, so play it safe and disallow all
+   * protocols to start with, and re-add the wanted ones back in.
+   */
+  *val = 0;
+
   if(!str)
     return CURLE_BAD_FUNCTION_ARGUMENT;
 
@@ -163,8 +169,6 @@ static CURLcode protocol2num(const char *str, curl_prot_t *val)
     return CURLE_OK;
   }
 
-  *val = 0;
-
   do {
     const char *token = str;
     size_t tlen;
@@ -2654,22 +2658,18 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option, va_list param)
     break;
 
   case CURLOPT_PROTOCOLS_STR: {
-    curl_prot_t prot;
     argptr = va_arg(param, char *);
-    result = protocol2num(argptr, &prot);
+    result = protocol2num(argptr, &data->set.allowed_protocols);
     if(result)
       return result;
-    data->set.allowed_protocols = prot;
     break;
   }
 
   case CURLOPT_REDIR_PROTOCOLS_STR: {
-    curl_prot_t prot;
     argptr = va_arg(param, char *);
-    result = protocol2num(argptr, &prot);
+    result = protocol2num(argptr, &data->set.redir_protocols);
     if(result)
       return result;
-    data->set.redir_protocols = prot;
     break;
   }
 
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index c20f90d945..b80ffb618e 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -187,7 +187,7 @@ test1439 test1440 test1441 test1442 test1443 test1444 test1445 test1446 \
 test1447 test1448 test1449 test1450 test1451 test1452 test1453 test1454 \
 test1455 test1456 test1457 test1458 test1459 test1460 test1461 test1462 \
 test1463 test1464 test1465 test1466 test1467 test1468 test1469 test1470 \
-test1471 test1472 test1473          test1475 test1476 test1477 test1478 \
+test1471 test1472 test1473 test1474 test1475 test1476 test1477 test1478 \
 \
 test1500 test1501 test1502 test1503 test1504 test1505 test1506 test1507 \
 test1508 test1509 test1510 test1511 test1512 test1513 test1514 test1515 \
diff --git a/tests/data/test1474 b/tests/data/test1474
new file mode 100644
index 0000000000..c66fa28104
--- /dev/null
+++ b/tests/data/test1474
@@ -0,0 +1,42 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP GET
+--proto
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+none
+</server>
+<features>
+http
+</features>
+<name>
+--proto -all disables all protocols
+</name>
+<command>
+--proto -all http://%HOSTIP:%NOLISTENPORT/%TESTNUMBER
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+# 1 - Protocol "http" disabled
+<errorcode>
+1
+</errorcode>
+</verify>
+</testcase>