diff --git a/source/test/intltest/intltest.cpp b/source/test/intltest/intltest.cpp
index c788e9a..8a717e4 100644
--- a/source/test/intltest/intltest.cpp
+++ b/source/test/intltest/intltest.cpp
@@ -1790,6 +1790,9 @@
 }
 
 UBool IntlTest::assertSuccess(const char* message, UErrorCode ec, UBool possibleDataError, const char *file, int line) {
+    if( file==NULL ) {
+      file = ""; // prevent failure if no file given
+    }
     if (U_FAILURE(ec)) {
         if (possibleDataError) {
           dataerrln("FAIL: %s:%d: %s (%s)", file, line, message, u_errorName(ec));