diff --git a/icu4c/source/test/cintltst/ulocbuildertst.c b/icu4c/source/test/cintltst/ulocbuildertst.c
index 781ff3a32eef..e0d84eeb1e25 100644
--- a/icu4c/source/test/cintltst/ulocbuildertst.c
+++ b/icu4c/source/test/cintltst/ulocbuildertst.c
@@ -1130,6 +1130,7 @@ static void TestAddRemoveUnicodeLocaleAttributeWellFormed() {
     }
 }
 
+*/
 static void TestAddUnicodeLocaleAttributeIllFormed() {
     static const char* illFormed[] = {
         "aa",
@@ -1143,18 +1144,22 @@ static void TestAddUnicodeLocaleAttributeIllFormed() {
         "1ZB30zfk9-abc",
         "2ck30zfk9-adsf023-234kcZ",
     };
-    for (const char* ill : illFormed) {
+    for (int i = 0; i < UPRV_LENGTHOF(illFormed); i++) {
+        const char* ill = illFormed[i];
         UErrorCode status = U_ZERO_ERROR;
-        LocaleBuilder bld;
-        bld.addUnicodeLocaleAttribute(ill);
-        Locale loc = bld.build(status);
+        ULocaleBuilder bld = ulb_open();
+        ulb_addUnicodeLocaleAttribute(bld, ill);
+        char buffer[ULOC_FULLNAME_CAPACITY];
+        ulb_build(bld, buffer, ULOC_FULLNAME_CAPACITY, &status);
         if (status != U_ILLEGAL_ARGUMENT_ERROR) {
-            errln("addUnicodeLocaleAttribute(\"%s\") should fail but has no Error\n",
+            log_err("addUnicodeLocaleAttribute(\"%s\") should fail but has no Error\n",
                   ill);
         }
+        ulb_close(bld);
     }
 }
 
+/*
 static void TestSetExtensionU() {
     LocaleBuilder bld;
     bld.setLanguage("zh");
@@ -1706,7 +1711,9 @@ void addLocaleBuilderTest(TestNode** root)
   /*
     TESTCASE(TestAddRemoveUnicodeLocaleAttribute);
     TESTCASE(TestAddRemoveUnicodeLocaleAttributeWellFormed);
+    */
     TESTCASE(TestAddUnicodeLocaleAttributeIllFormed);
+    /*
     TESTCASE(TestSetExtensionU);
     TESTCASE(TestSetExtensionValidateUWellFormed);
     TESTCASE(TestSetExtensionValidateUIllFormed);