diff --git a/cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/test.cpp b/cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/test.cpp
index aa7f16bdd00..ceffdf11fa9 100644
--- a/cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/test.cpp
+++ b/cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/test.cpp
@@ -1,11 +1,16 @@
 typedef int FILE;
 #define NULL (0)
 FILE *fopen(char *filename, const char *mode);
+FILE *fdopen(int handle, char *mode);
 char * tmpnam(char * name);
+int mkstemp(char * name);
+char * strcat(char *str1, const char *str2);
+int umask(int pmode);
+int chmod(char * filename,int pmode);
 int fprintf(FILE *fp,const char *fmt, ...);
 int fclose(FILE *stream);
 
-int main(int argc, char *argv[])
+int funcTest1()
 {
   FILE *fp;
   char *filename = tmpnam(NULL); // BAD
@@ -14,3 +19,50 @@ int main(int argc, char *argv[])
   fclose(fp);
   return 0;
 }
+
+int funcTest2()
+{
+  FILE *fp;
+  int fd;
+  char filename[80];
+  strcat (filename, "/tmp/name.XXXXXX");
+  fd = mkstemp(filename);
+  if ( fd < 0 ) {
+    return 1;
+  }
+  fp = fdopen(fd,"w"); // GOOD
+  return 0;
+}
+
+int funcTest3()
+{
+  FILE *fp;
+  char filename[80];
+  strcat(filename, "/tmp/tmp.name");
+  fp = fopen(filename,"w"); // BAD
+  fprintf(fp,"%s\n","data to file");
+  fclose(fp);
+  return 0;
+}
+
+int funcTest4()
+{
+  FILE *fp;
+  char filename[80];
+  umask(0022);
+  strcat(filename, "/tmp/tmp.name");
+  fp = fopen(filename,"w"); // GOOD
+  chmod(filename,0666);
+  fprintf(fp,"%s\n","data to file");
+  fclose(fp);
+  return 0;
+}
+
+int main(int argc, char *argv[])
+{
+  funcTest1();
+  funcTest2();
+  funcTest3();
+  funcTest4();
+  return 0;
+}