diff --git a/icu4c/source/test/cintltst/cbiapts.c b/icu4c/source/test/cintltst/cbiapts.c
index 7cea5c6a86b..a148636b988 100644
--- a/icu4c/source/test/cintltst/cbiapts.c
+++ b/icu4c/source/test/cintltst/cbiapts.c
@@ -903,6 +903,9 @@ static void TestBug11665(void) {
     ctest_resetICU();
     bi = ubrk_open(UBRK_WORD, "en_US", japaneseText, UPRV_LENGTHOF(japaneseText), &status);
     TEST_ASSERT_SUCCESS(status);
+    if (!bi) {
+        return;
+    }
     for (brk=ubrk_first(bi); brk != UBRK_DONE; brk=ubrk_next(bi)) {
         boundaries[brkIdx] = brk;
         if (++brkIdx >= UPRV_LENGTHOF(boundaries) - 1) {
diff --git a/icu4c/source/test/cintltst/cnumtst.c b/icu4c/source/test/cintltst/cnumtst.c
index 7e02ca68352..dbb40fed218 100644
--- a/icu4c/source/test/cintltst/cnumtst.c
+++ b/icu4c/source/test/cintltst/cnumtst.c
@@ -2814,7 +2814,7 @@ static void TestVariousStylesAndAttributes(void) {
         UErrorCode status = U_ZERO_ERROR;
         UNumberFormat * unum = unum_open(lsaTestPtr->style, NULL, 0, lsaTestPtr->locale, NULL, &status);
         if ( U_FAILURE(status) ) {
-            log_err("FAIL: unum_open style %d, locale %s: error %s\n", (int)lsaTestPtr->style, lsaTestPtr->locale, u_errorName(status));
+            log_data_err("FAIL: unum_open style %d, locale %s: error %s\n", (int)lsaTestPtr->style, lsaTestPtr->locale, u_errorName(status));
         } else {
             const ValueAndExpectedString * veItemPtr;
             if (lsaTestPtr->attribute >= 0) {
diff --git a/icu4c/source/test/intltest/datadrivennumberformattestsuite.cpp b/icu4c/source/test/intltest/datadrivennumberformattestsuite.cpp
index 6d760ae97ae..d3c650c2470 100644
--- a/icu4c/source/test/intltest/datadrivennumberformattestsuite.cpp
+++ b/icu4c/source/test/intltest/datadrivennumberformattestsuite.cpp
@@ -168,7 +168,7 @@ void DataDrivenNumberFormatTestSuite::showFailure(const UnicodeString &message)
     uprv_itou(
             lineStr, UPRV_LENGTHOF(lineStr), (uint32_t) fFileLineNumber, 10, 1);
     UnicodeString fullMessage("line ");
-    errln(fullMessage.append(lineStr).append(": ")
+    dataerrln(fullMessage.append(lineStr).append(": ")
             .append(prettify(message)));
     showLineInfo();
 }
diff --git a/icu4c/source/test/intltest/tsmthred.cpp b/icu4c/source/test/intltest/tsmthred.cpp
index 249a78a8ee8..1a5fdc62f5a 100644
--- a/icu4c/source/test/intltest/tsmthred.cpp
+++ b/icu4c/source/test/intltest/tsmthred.cpp
@@ -691,7 +691,7 @@ public:
         status = U_ZERO_ERROR;
         LocalPointer<NumberFormat> formatter(NumberFormat::createInstance(Locale::getEnglish(),status));
         if(U_FAILURE(status)) {
-            IntlTest::gTest->errln("%s:%d Error %s on NumberFormat::createInstance().",
+            IntlTest::gTest->dataerrln("%s:%d Error %s on NumberFormat::createInstance().",
                     __FILE__, __LINE__, u_errorName(status));
             goto cleanupAndReturn;
         }
@@ -1460,6 +1460,9 @@ void MultithreadTest::TestBreakTranslit() {
 
     gSharedTransliterator = Transliterator::createInstance(
         UNICODE_STRING_SIMPLE("Any-Latin; Lower; NFD; [:Diacritic:]Remove; NFC; Latin-ASCII;"), UTRANS_FORWARD, status);
+    if (!gSharedTransliterator) {
+         return;
+     }
     TSMTHREAD_ASSERT_SUCCESS(status); 
 
     UnicodeString expected(*gTranslitInput);