diff --git a/test_drivers/negative/negative.cpp b/test_drivers/negative/negative.cpp
index b1af5f7..571e6c6 100644
--- a/test_drivers/negative/negative.cpp
+++ b/test_drivers/negative/negative.cpp
@@ -4,9 +4,12 @@ using namespace utf8;
 #include <string>
 #include <iostream>
 #include <fstream>
+#include <algorithm>
 using namespace std;
 
 const char* TEST_FILE_PATH = "../../test_data/negative/utf8_invalid.txt";
+const unsigned INVALID_LINES[] = { 75, 76, 82, 83, 84, 85, 93, 102, 103, 105, 106, 107, 108, 109, 110, 114, 115, 116, 117, 124, 125, 130, 135, 140, 145, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 169, 175, 176, 177, 207, 208, 209, 210, 211, 220, 221, 222, 223, 224, 232, 233, 234, 235, 236, 247, 248, 249, 250, 251, 252, 253, 257, 258, 259, 260, 261, 262, 263, 264, 268, 269}; 
+const unsigned* INVALID_LINES_END = INVALID_LINES + sizeof(INVALID_LINES)/sizeof(unsigned);
 
 int main()
 {
@@ -27,7 +30,10 @@ int main()
 
         line_count++;
 	// Print out lines that contain invalid UTF-8
-	if (!is_valid(line.begin(), line.end()))
-            cout << line_count << ": " << line << '\n';
+	if (!is_valid(line.begin(), line.end())) {
+	   const unsigned* u = find(INVALID_LINES, INVALID_LINES_END, line_count);
+	   if (u == INVALID_LINES_END) 
+	       cout << "Unexpected invalid utf-8 at line " << line_count << '\n';
+        }
     }
 }
diff --git a/test_drivers/runtests.pl b/test_drivers/runtests.pl
index 71ffa42..c939497 100755
--- a/test_drivers/runtests.pl
+++ b/test_drivers/runtests.pl
@@ -30,3 +30,11 @@ chdir '..';
 die if !open(REPORT, ">>$report_name");
 print REPORT "==================End of regression test==================\n";
 print REPORT "\n";
+print REPORT "==================Negative Test ==================\n"; 
+close($report_name);
+chdir 'negative';
+`./negative >> ../$report_name`;
+chdir '..';
+die if !open(REPORT, ">>$report_name");
+print REPORT "==================End of negative test==================\n";
+print REPORT "\n";