diff --git a/check_smart/check_smart.cpp b/check_smart/check_smart.cpp
index 985f66a..dcab69d 100644
--- a/check_smart/check_smart.cpp
+++ b/check_smart/check_smart.cpp
@@ -2,76 +2,80 @@
 
 const char *servicename = (const char*)"SMART";
 
-int getSmartAttrValue(string line)
-{
+int getSmartAttrValue(string line) {
   return stoi(line.substr(line.find_last_of(" ")+1));
 }
 
-int getSmartAttrID(string line)
-{
+int getSmartAttrID(string line) {
   size_t first = line.find_first_not_of(' ');
   size_t last = line.find_first_of(' ',first);
   int id = -1;
-  try {id = stoi(line.substr(first,last-first));}
-  catch(...){}
+  try {
+    id = stoi(line.substr(first,last-first));
+  }
+  catch(...){
+    return -1;
+  }
   return id;
 }
 
-int checkDriveType(const char* disk)
-{
+int checkDriveType(const char* disk) {
   string output = "";
   string RRLine = "";
   string line= "";
 
   int rc = run_smartctl_cmd(string(SMARTCTL_CMD_INFO), disk,&output);
-  if(rc)
-  {
+  if(rc) {
     cout << "Error reading SMART data from disk " << disk << endl;
     exit(3);
   }
 
   stringstream sstream;
   sstream.str(output);
-  while(getline(sstream,line) && RRLine == "")
-  {
+  while(getline(sstream,line) && RRLine == "") {
     size_t found = line.find(ROTATION_INFO_STR);
-    if(found != string::npos) {RRLine = line;}
+    if(found != string::npos) {
+      RRLine = line;
+    }
   }
-  if(RRLine != "")
-  {
+  if(RRLine != "") {
     size_t found = RRLine.find(SSD_DEV_STR);
-    if(found != string::npos) {return SSD;}
+    if(found != string::npos) {
+      return SSD;
+    }
   }
   return HDD;
 }
 
-map<int,SMARTAttr> prepareAttrMap(int driveType)
-{
+map<int,SMARTAttr> prepareAttrMap(int driveType) {
   map<int,SMARTAttr> map;
 
   SMARTAttr realloc;
   realloc.name = "Reallocated_Sector_Ct";
   realloc.value = -1;
   realloc.severity = WARN;
+  realloc.optional = false;
   map[REALLOC_SEC_COUNT_ID] = realloc;
 
   SMARTAttr pending;
   SMARTAttr off_uncorrect;
   SMARTAttr wear;
+  SMARTAttr wearout;
   SMARTAttr badblocks;
   SMARTAttr rep_uncorrect;
 
-  switch(driveType)
-  {
+  switch(driveType) {
     case HDD:
       pending.name = "Current_Pending_Sector";
       pending.value = -1;
       pending.severity = CRIT;
+      pending.optional = false;
       map[CURRENT_PENDING_SEC_ID] = pending;
 
       off_uncorrect.name = "Offline_Uncorrectable";
       off_uncorrect.value = -1;
       off_uncorrect.severity = CRIT;
+      off_uncorrect.optional = false;
       map[OFFLINE_UNCORRECT_ID] = off_uncorrect;
 
       break;
@@ -79,16 +83,25 @@ map<int,SMARTAttr> prepareAttrMap(int driveType)
       wear.name = "Wear_Leveling_Count";
       wear.value = -1;
       wear.severity = WARN;
+      wear.optional = true;
       map[WEAR_COUNT_ID] = wear;
 
+      wearout.name = "Media_Wearout_Indicator";
+      wearout.value = -1;
+      wearout.severity = WARN;
+      wearout.optional = true;
+      map[WEAR_COUNT_ID] = wearout;
+
       badblocks.name = "Runtime_Bad_Block";
       badblocks.value = -1;
       badblocks.severity = CRIT;
+      badblocks.optional = false;
       map[RUNTIME_BAD_BLOCKS_IDD] = badblocks;
 
       rep_uncorrect.name = "Reported_Uncorrect";
       rep_uncorrect.value = -1;
       rep_uncorrect.severity = CRIT;
+      rep_uncorrect.optional = false;
       map[REP_UNCORRECT_ID] = rep_uncorrect;
 
       break;
@@ -96,14 +109,12 @@ map<int,SMARTAttr> prepareAttrMap(int driveType)
   return map;
 }
 
-int evalStatus(const char* disk, int driveType, string *status)
-{
+int evalStatus(const char* disk, int driveType, string *status) {
   string output = "";
   string line = "";
 
   int rc = run_smartctl_cmd(string(SMARTCTL_CMD_ATTRS), disk,&output);
-  if(rc)
-  {
+  if(rc) {
     cout << "Error reading SMART data from disk " << disk << endl;
     exit(UNKN);
   }
@@ -112,34 +123,42 @@ int evalStatus(const char* disk, int driveType, string *status)
 
   stringstream sstream;
   sstream.str(output);
-  while(getline(sstream,line))
-  {
-    for(map<int,SMARTAttr>::iterator it = attrMap.begin(); it != attrMap.end(); ++it)
-    {
+  while(getline(sstream,line)) {
+    for(map<int,SMARTAttr>::iterator it = attrMap.begin(); it != attrMap.end(); ++it) {
       int id = it->first;
-      if(getSmartAttrID(line) == id) {attrMap[id].value = getSmartAttrValue(line);}
+      int attrID = getSmartAttrID(line);
+      if(attrID == -1) {
+        continue;
+      }
+      if(getSmartAttrID(line) == id) {
+        attrMap[id].value = getSmartAttrValue(line);
+      }
     }
   }
   int ret = OK;
   *status = string(disk);
-  for(map<int,SMARTAttr>::iterator it = attrMap.begin(); it != attrMap.end(); ++it)
-  {
+  for(map<int,SMARTAttr>::iterator it = attrMap.begin(); it != attrMap.end(); ++it) {
     int id = it->first;
     SMARTAttr attr = it->second;
 
-    if(attr.value == -1)
-    {
+    if(attr.value == -1) {
+      if(attr.optional) {
+        continue;
+      }
       *status = string(disk) + " status UNKNOWN";
       return UNKN;
     }
     int veredict = 0;
-    if(attr.value) {veredict = attr.severity;}
-    switch(veredict)
-    {
+    if(attr.value) {
+      veredict = attr.severity;
+    }
+    switch(veredict) {
       case OK:
         break;
       case WARN:
-        if(ret == OK) {ret = WARN;}
+        if(ret == OK) {
+          ret = WARN;
+        }
         break;
       case CRIT:
         ret = CRIT;
@@ -150,8 +169,7 @@ int evalStatus(const char* disk, int driveType, string *status)
   return ret;
 }
 
-int run_smartctl_cmd(const string command, const char* disk, string* output)
-{
+int run_smartctl_cmd(const string command, const char* disk, string* output) {
   int uid = getuid();
   setreuid(0,0);
 
@@ -161,15 +179,12 @@ int run_smartctl_cmd(const string command, const char* disk, string* output)
   return rc;
 }
 
-void printVersion()
-{
+void printVersion() {
   cout << "check_smart v" << VERSION << endl << endl;
 }
 
-void printHelp(bool longVersion)
-{
-  if(longVersion)
-  {
+void printHelp(bool longVersion) {
+  if(longVersion) {
     printVersion();
     cout << "Checks for pending, reallocated or uncorrectable sectors in disks using SMART" << endl << "WARNING: Requires the setuid bit to be set to run as root" << endl << endl;
     printHelp(false);
@@ -185,8 +200,7 @@ void printHelp(bool longVersion)
   cout << "Usage: " << endl << "check_smart [-hV] DISKS..." << endl << endl;
 }
 
-void set_timeout(unsigned int sec)
-{
+void set_timeout(unsigned int sec) {
   struct itimerval timer;
   timer.it_value.tv_sec = sec;
   timer.it_value.tv_usec = 0;
@@ -200,14 +214,11 @@ void set_timeout(unsigned int sec)
   sigaction (SIGVTALRM, &sa, 0);
 }
 
-int main(int argc, char **argv)
-{
+int main(int argc, char **argv) {
   set_timeout(10);
   int c;
-  while ((c = getopt (argc, argv, "Vh")) != -1)
-  {
-    switch(c)
-    {
+  while ((c = getopt (argc, argv, "Vh")) != -1) {
+    switch(c) {
       case 'h':
         printHelp(true);
 	return OK;
@@ -220,8 +231,7 @@ int main(int argc, char **argv)
     }
   }
 
-  if(argc == 1)
-  {
+  if(argc == 1) {
     cout << "No disks checked" << endl;
     return 3;
   }
@@ -229,11 +239,9 @@ int main(int argc, char **argv)
   string *results = new string[argc-1];
   int returnCode = OK;
 
-  for(int i = 1; i < argc; i++)
-  {
+  for(int i = 1; i < argc; i++) {
     int driveType = checkDriveType(argv[i]);
-    switch(driveType)
-    {
+    switch(driveType) {
       case HDD:
       case SSD:
         break;
@@ -243,8 +251,7 @@ int main(int argc, char **argv)
         break;
     }
 
-    switch(evalStatus(argv[i],driveType,&(results[i-1])))
-    {
+    switch(evalStatus(argv[i],driveType,&(results[i-1]))) {
       case OK:
         break;
       case WARN:
@@ -253,6 +260,9 @@ int main(int argc, char **argv)
       case CRIT:
         returnCode = CRIT;
         break;
+      case UNKN:
+        returnCode = UNKN;
+        break;
     }
   }
 
@@ -261,8 +271,7 @@ int main(int argc, char **argv)
   else if(returnCode == WARN) {cout << " WARNING - disk status: ";}
   else if(returnCode == CRIT) {cout << " CRITICAL - disk status: ";}
   else if(returnCode == UNKN) {cout << " UNKNOWN - disk status: ";}
-  for(int i = 0; i < (argc-1); i++)
-  {
+  for(int i = 0; i < (argc-1); i++) {
     cout << results[i];
     if(i != (argc-2)) {cout << ", ";}
   }
diff --git a/check_smart/check_smart.h b/check_smart/check_smart.h
index 877cce3..ac61fe7 100755
--- a/check_smart/check_smart.h
+++ b/check_smart/check_smart.h
@@ -31,6 +31,7 @@
 #define CURRENT_PENDING_SEC_ID 197
 #define OFFLINE_UNCORRECT_ID 198
 #define WEAR_COUNT_ID 177
+#define MEDIA_WEAROUT_INDICATOR 233
 #define RUNTIME_BAD_BLOCKS_IDD 183
 #define REP_UNCORRECT_ID 187
 
@@ -44,6 +45,7 @@ struct SMARTAttr
   string name;
   int value;
   int severity;
+  bool optional;
 }; typedef struct SMARTAttr SMARTAttr;