--- a/src/cmds/pbsnodes.c	2015-03-17 16:43:36.000000000 -0400
+++ b/src/cmds/pbsnodes.c	2019-02-25 12:33:37.824638386 -0500
@@ -693,7 +693,7 @@
         /* -N n is the same as -N ""  -- it clears the note */
 
         if (!strcmp(note, "n"))
-          *note = '\0';
+          *note = NULL;
 
         if (strlen(note) > MAX_NOTE)
           {
@@ -821,7 +821,7 @@
         {
         nodeargs = (char **)calloc(2, sizeof(char **));
         nodeargs[0] = strdup("");
-        nodeargs[1] = '\0';
+        nodeargs[1] = NULL;
         }
       }
     }
@@ -901,7 +901,7 @@
 
         MXMLCreateE(&DE, "Data");
 
-        for (lindex = 0;nodeargs[lindex] != '\0';lindex++)
+        for (lindex = 0;nodeargs[lindex] != NULL;lindex++)
           {
           bstatus = statnode(con, nodeargs[lindex]);
 
@@ -922,7 +922,7 @@
         }
       else
         {
-        for (lindex = 0;nodeargs[lindex] != '\0';lindex++)
+        for (lindex = 0;nodeargs[lindex] != NULL;lindex++)
           {
           bstatus = statnode(con, nodeargs[lindex]);
 
@@ -946,7 +946,7 @@
 
       /* list any node that is DOWN, OFFLINE, or UNKNOWN */
 
-      for (lindex = 0;nodeargs[lindex] != '\0';lindex++)
+      for (lindex = 0;nodeargs[lindex] != NULL;lindex++)
         {
         bstatus = statnode(con, nodeargs[lindex]);
 
--- a/src/cmds/qsub_functions.c	2015-03-17 16:43:36.000000000 -0400
+++ b/src/cmds/qsub_functions.c	2019-02-25 12:32:00.442982091 -0500
@@ -542,7 +542,7 @@
   static char tmpLine[65536];
 
   /* we've reached the end */
-  if ((start == NULL) && (*tok_ptr == '\0'))
+  if ((start == NULL) && (*tok_ptr == NULL))
     return(0);
 
   if (start != NULL)
@@ -554,7 +554,7 @@
     return(0);
      
   if ((*curr_ptr == '=') || 
-      (*curr_ptr == '\0'))
+      (*curr_ptr == NULL))
     {
     /* no name, fail */
     return(-1);
@@ -574,18 +574,18 @@
 
   /* strip blanks */
   while ((*equals) && (isspace((int)*equals)))
-    *equals++ = '\0';
+    *equals++ = NULL;
 
   if (*equals != '=')
     return (-1); /* should have found a = as first non blank */
 
-  *equals++ = '\0';
+  *equals++ = NULL;
 
   /* skip leading white space */
   while (isspace((int)*equals) && *equals)
     equals++;
 
-  if (*equals == '\0')
+  if (*equals == NULL)
     return(-1);
 
   *value = equals;
@@ -872,7 +872,7 @@
   else
     {
     char *tmp_host = pbs_default();
-    if (tmp_host == '\0')
+    if (tmp_host == NULL)
       hash_add_or_exit(mm, job_attr, ATTR_pbs_o_server, qsub_host, LOGIC_DATA);
     else
       hash_add_or_exit(mm, job_attr, ATTR_pbs_o_server, tmp_host, LOGIC_DATA);
--- a/src/include/attribute.h	2015-03-17 16:43:36.000000000 -0400
+++ b/src/include/attribute.h	2019-02-22 16:47:40.507695453 -0500
@@ -445,7 +445,7 @@
 extern int   parse_equal_string(char *, char **, char **);
 extern char *parse_comma_string(char *,char **);
 
-#define NULL_FUNC '\0'
+#define NULL_FUNC NULL
 
 /* other associated funtions */
 struct dynamic_string;
--- a/src/resmom/mom_main.c	2015-03-17 16:43:36.000000000 -0400
+++ b/src/resmom/mom_main.c	2019-02-22 14:01:26.573890840 -0500
@@ -4224,7 +4224,7 @@
     goto done;
     }
 
-  name[i] = '\0';
+  name[i] = NULL;
 
   for (d = ret_string, resline++;*resline;)
     {
--- a/src/server/job_attr_def.c	2015-03-17 16:43:36.000000000 -0400
+++ b/src/server/job_attr_def.c	2019-02-22 16:43:05.653007840 -0500
@@ -1193,7 +1193,7 @@
   },
 
   /* JOB_ATR_system_start_time */
-  {ATTR_system_start_time, /* start time as encoded in the proc/pid directory */
+  { (char *)ATTR_system_start_time, /* start time as encoded in the proc/pid directory */
    decode_l,
    encode_l,
    set_l,
@@ -1205,7 +1205,7 @@
    PARENT_TYPE_JOB},
 
   /* JOB_ATR_nppcu */
-  {ATTR_nppcu, /* how to handle compute units (on Cray system) */
+  { (char *)ATTR_nppcu, /* how to handle compute units (on Cray system) */
    decode_l,
    encode_l,
    set_l,