diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index d41052e539..d849c3b1a7 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -193,7 +193,7 @@ test1508 test1509 test1510 test1511 test1512 test1513 test1514 test1515 \
 test1516 test1517 test1518 test1519 test1520 test1521 test1522 test1523 \
 test1524 test1525 test1526 test1527 test1528 test1529 test1530 test1531 \
 test1532 test1533 test1534 test1535 test1536 test1537 test1538 test1539 \
-test1540          test1542 \
+test1540          test1542 test1543 \
 \
 test1550 test1551 test1552 test1553 test1554 test1555 test1556 test1557 \
 test1558 test1559 test1560 test1561 test1562 test1563 test1564 test1565 \
diff --git a/tests/data/test1543 b/tests/data/test1543
new file mode 100644
index 0000000000..be7ede2092
--- /dev/null
+++ b/tests/data/test1543
@@ -0,0 +1,76 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+CURLOPT_CURLU
+</keywords>
+</info>
+#
+# Similar to 1518 but using CURLOPT_CURLU
+#
+# Server-side
+<reply>
+<data2 nocheck="yes">
+HTTP/1.1 200 OK
+Date: Thu, 17 Mar 2016 14:41:00 GMT
+Server: test-server/fake
+X-Special: swsclose
+Content-Length: 0
+Connection: close
+
+</data2>
+<data nocheck="yes">
+HTTP/1.1 302 redirect
+Date: Thu, 17 Mar 2016 14:41:00 GMT
+Server: test-server/fake
+Content-Type: text/plain; charset=US-ASCII
+Location: ../%TESTNUMBER0002
+Content-Length: 0
+Connection: close
+
+</data>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+# tool is what to use instead of 'curl'
+<tool>
+lib%TESTNUMBER
+</tool>
+
+<name>
+CURLOPT_CURLU, URL with space and CURLINFO_EFFECTIVE_URL
+</name>
+<command>
+"http://%HOSTIP:%HTTPPORT/ /with/ space/ /file"
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+GET /%20/with/%20space/%20/file HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+GET /%20/with/%20space/%TESTNUMBER0002 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+</protocol>
+<stdout>
+res 0
+status 200
+redirects 1
+effectiveurl http://%HOSTIP:%HTTPPORT/%20/with/%20space/%TESTNUMBER0002
+redirecturl blank
+</stdout>
+<errorcode>
+0
+</errorcode>
+</verify>
+</testcase>
diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index 2f9aa2f91c..c105906cdb 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -55,7 +55,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect                \
  lib1518         lib1520 lib1521 lib1522 lib1523 \
  lib1525 lib1526 lib1527 lib1528 lib1529 lib1530 lib1531 lib1532 lib1533 \
  lib1534 lib1535 lib1536 lib1537 lib1538 lib1539 \
- lib1540         lib1542 \
+ lib1540         lib1542 lib1543 \
  lib1550 lib1551 lib1552 lib1553 lib1554 lib1555 lib1556 lib1557 \
  lib1558 lib1559 lib1560 lib1564 lib1565 lib1567 lib1568 lib1569 \
  lib1591 lib1592 lib1593 lib1594 lib1596 \
@@ -579,6 +579,9 @@ lib1542_SOURCES = lib1542.c $(SUPPORTFILES) $(TESTUTIL) $(TSTTRACE) $(WARNLESS)
 lib1542_LDADD = $(TESTUTIL_LIBS)
 lib1542_CPPFLAGS = $(AM_CPPFLAGS)
 
+lib1543_SOURCES = lib1518.c $(SUPPORTFILES)
+lib1543_CPPFLAGS = $(AM_CPPFLAGS) -DLIB1543
+
 lib1550_SOURCES = lib1550.c $(SUPPORTFILES)
 lib1550_CPPFLAGS = $(AM_CPPFLAGS) -DLIB1517
 
diff --git a/tests/libtest/lib1518.c b/tests/libtest/lib1518.c
index 8c4687885f..9d18fef36c 100644
--- a/tests/libtest/lib1518.c
+++ b/tests/libtest/lib1518.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -25,6 +25,16 @@
 
 /* Test inspired by github issue 3340 */
 
+static size_t writecb(char *buffer, size_t size, size_t nitems,
+                      void *outstream)
+{
+  (void)buffer;
+  (void)size;
+  (void)nitems;
+  (void)outstream;
+  return 0;
+}
+
 int test(char *URL)
 {
   CURL *curl;
@@ -33,17 +43,34 @@ int test(char *URL)
   long curlRedirectCount;
   char *effectiveUrl = NULL;
   char *redirectUrl = NULL;
-
+#ifdef LIB1543
+  CURLU *urlu = NULL;
+#endif
   curl = curl_easy_init();
   if(!curl) {
     fprintf(stderr, "curl_easy_init() failed\n");
     curl_global_cleanup();
     return TEST_ERR_MAJOR_BAD;
   }
-
+#ifdef LIB1543
+  /* set CURLOPT_URLU */
+  {
+    CURLUcode rc = CURLUE_OK;
+    urlu = curl_url();
+    if(urlu)
+      rc = curl_url_set(urlu, CURLUPART_URL, URL, CURLU_ALLOW_SPACE);
+    if(!urlu || rc) {
+      goto test_cleanup;
+    }
+    test_setopt(curl, CURLOPT_CURLU, urlu);
+  }
+  test_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+#else
   test_setopt(curl, CURLOPT_URL, URL);
   /* just to make it explicit and visible in this test: */
   test_setopt(curl, CURLOPT_FOLLOWLOCATION, 0L);
+#endif
+
 
   /* Perform the request, res will get the return code */
   res = curl_easy_perform(curl);
@@ -52,6 +79,7 @@ int test(char *URL)
   curl_easy_getinfo(curl, CURLINFO_REDIRECT_COUNT, &curlRedirectCount);
   curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &effectiveUrl);
   curl_easy_getinfo(curl, CURLINFO_REDIRECT_URL, &redirectUrl);
+  res = curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writecb);
 
   printf("res %d\n"
          "status %d\n"
@@ -62,13 +90,15 @@ int test(char *URL)
          (int)curlResponseCode,
          (int)curlRedirectCount,
          effectiveUrl,
-         redirectUrl);
+         redirectUrl ? redirectUrl : "blank");
 
 test_cleanup:
 
   /* always cleanup */
   curl_easy_cleanup(curl);
   curl_global_cleanup();
-
+#ifdef LIB1543
+  curl_url_cleanup(urlu);
+#endif
   return res;
 }