diff --git a/lib/urlapi.c b/lib/urlapi.c
index 103e0a6b57..24b8bc244a 100644
--- a/lib/urlapi.c
+++ b/lib/urlapi.c
@@ -1912,11 +1912,11 @@ CURLUcode curl_url_set(CURLU *u, CURLUPart what,
         return cc2cu(result);
       p = curlx_dyn_ptr(&enc);
       while(*p) {
-        /* make sure percent encoded are lower case */
+        /* make sure percent encoded are upper case */
         if((*p == '%') && ISXDIGIT(p[1]) && ISXDIGIT(p[2]) &&
-           (ISUPPER(p[1]) || ISUPPER(p[2]))) {
-          p[1] = Curl_raw_tolower(p[1]);
-          p[2] = Curl_raw_tolower(p[2]);
+           (ISLOWER(p[1]) || ISLOWER(p[2]))) {
+          p[1] = Curl_raw_toupper(p[1]);
+          p[2] = Curl_raw_toupper(p[2]);
           p += 3;
         }
         else
diff --git a/tests/data/Makefile.am b/tests/data/Makefile.am
index 3f520af253..7216d0a7c9 100644
--- a/tests/data/Makefile.am
+++ b/tests/data/Makefile.am
@@ -214,6 +214,7 @@ test1596 test1597 test1598 test1599 test1600 test1601 test1602 test1603 \
 test1604 test1605 test1606 test1607 test1608 test1609 test1610 test1611 \
 test1612 test1613 test1614 test1615 test1616 test1617 test1618 test1619 \
 test1620 test1621 test1622 test1623 test1624 test1625 test1626 test1627 \
+test1628 \
 \
 test1630 test1631 test1632 test1633 test1634 test1635 test1636 test1637 \
 test1638 test1639 test1640 test1641 test1642 test1643 test1644 \
diff --git a/tests/data/test1221 b/tests/data/test1221
index 322a5f878f..5ff7add995 100644
--- a/tests/data/test1221
+++ b/tests/data/test1221
@@ -44,7 +44,7 @@ content to _?!#$'|%LT%GT
 # Verify data after the test has been "shot"
 <verify>
 <protocol crlf="yes" nonewline="yes">
-POST /%TESTNUMBER?my+name+is+moo%5b%5d%AMPyes=s+i+r%AMPv_alue=content+to+_%3f%21%23%24%27%7c%3c%3e%0a%AMPcontent+to+_%3f%21%23%24%27%7c%3c%3e%0a%AMP%3d%3d HTTP/1.1
+POST /%TESTNUMBER?my+name+is+moo%5B%5D%AMPyes=s+i+r%AMPv_alue=content+to+_%3F%21%23%24%27%7C%3C%3E%0A%AMPcontent+to+_%3F%21%23%24%27%7C%3C%3E%0A%AMP%3D%3D HTTP/1.1
 Host: %HOSTIP:%HTTPPORT
 User-Agent: curl/%VERSION
 Accept: */*
diff --git a/tests/data/test1628 b/tests/data/test1628
new file mode 100644
index 0000000000..d5cf836787
--- /dev/null
+++ b/tests/data/test1628
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="US-ASCII"?>
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP PUT
+</keywords>
+</info>
+# Server-side
+<reply>
+<data>
+HTTP/1.0 200 OK swsclose
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+
+blablabla
+
+</data>
+</reply>
+
+# Client-side
+<client>
+<features>
+proxy
+</features>
+<server>
+http
+</server>
+<name>
+HTTP PUT from file with weird letters over a HTTP proxy
+</name>
+<command>
+-x http://%HOSTIP:%HTTPPORT http://ssss/ -T %LOGDIR/%TESTNUMBERte[]st.txt
+</command>
+<file name="%LOGDIR/%TESTNUMBERte[]st.txt">
+a few bytes
+</file>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<protocol crlf="headers">
+PUT http://ssss/%TESTNUMBERte%5B%5Dst.txt HTTP/1.1
+Host: ssss
+User-Agent: curl/%VERSION
+Accept: */*
+Proxy-Connection: Keep-Alive
+Content-Length: 12
+
+a few bytes
+</protocol>
+</verify>
+</testcase>
diff --git a/tests/libtest/lib1560.c b/tests/libtest/lib1560.c
index 6d42b35694..6c3fff9bc9 100644
--- a/tests/libtest/lib1560.c
+++ b/tests/libtest/lib1560.c
@@ -1137,8 +1137,8 @@ static const struct setcase set_parts_list[] = {
    "https://host:1234/",
    0, 0, CURLUE_OK, CURLUE_BAD_PORT_NUMBER},
   {"https://host/",
-   "path=%4A%4B%4C,",
-   "https://host/%4a%4b%4c",
+   "path=%4A%4b%4C,",
+   "https://host/%4A%4B%4C",
    0, 0, CURLUE_OK, CURLUE_OK},
   {"https://host/mooo?q#f",
    "path=NULL,query=NULL,fragment=NULL,",