diff --git a/test_conformance/printf/util_printf.cpp b/test_conformance/printf/util_printf.cpp
index 83a21fbb..0768adb5 100644
--- a/test_conformance/printf/util_printf.cpp
+++ b/test_conformance/printf/util_printf.cpp
@@ -1032,6 +1032,9 @@ testCase testCaseChar = {
 
 std::vector<printDataGenParameters> printStringGenParameters = {
 
+    // empty format, no data representation
+    { {""} },
+
     // empty format
     { {""}, "\"foo\"" },
 
@@ -1094,6 +1097,8 @@ std::vector<std::string> correctBufferString = {
 
     "",
 
+    "",
+
     " foo",
 
     "f",