diff --git a/src/tools-source/fl_wrapper/tpl_exec.c b/src/tools-source/fl_wrapper/tpl_exec.c
index 71dae84..8c7a386 100644
--- a/src/tools-source/fl_wrapper/tpl_exec.c
+++ b/src/tools-source/fl_wrapper/tpl_exec.c
@@ -17,13 +17,13 @@
  */
 
 extern RET_TYPE FUNCTION(P1);
-RET_TYPE (*orig_FUNCTION)(P1) = 0;
+RET_TYPE (*orig_FUNCTION)(P1) = NULL;
 
 RET_TYPE FUNCTION(P1)
 {
 	int old_errno=errno;
 
-	handle_file_access_after("FUNCTION", f, 0);
+	handle_file_access_after("FUNCTION", f, NULL);
 	if (!orig_FUNCTION) orig_FUNCTION = get_dl_symbol("FUNCTION");
 	errno=old_errno;
 
diff --git a/src/tools-source/fl_wrapper/tpl_open.c b/src/tools-source/fl_wrapper/tpl_open.c
index 60ece59..2e33441 100644
--- a/src/tools-source/fl_wrapper/tpl_open.c
+++ b/src/tools-source/fl_wrapper/tpl_open.c
@@ -17,7 +17,7 @@
  */
 
 extern RET_TYPE FUNCTION(P1);
-RET_TYPE (*orig_FUNCTION)(P1) = 0;
+RET_TYPE (*orig_FUNCTION)(P1) = NULL;
 
 RET_TYPE FUNCTION(P1)
 {
diff --git a/src/tools-source/fl_wrapper/tpl_rest.c b/src/tools-source/fl_wrapper/tpl_rest.c
index a67da9f..7410f0a 100644
--- a/src/tools-source/fl_wrapper/tpl_rest.c
+++ b/src/tools-source/fl_wrapper/tpl_rest.c
@@ -17,7 +17,7 @@
  */
 
 extern RET_TYPE FUNCTION(P1);
-RET_TYPE (*orig_FUNCTION)(P1) = 0;
+RET_TYPE (*orig_FUNCTION)(P1) = NULL;
 
 RET_TYPE FUNCTION(P1)
 {