diff --git a/RichString.c b/RichString.c
index fcb4e3589..e1350d16b 100644
--- a/RichString.c
+++ b/RichString.c
@@ -190,7 +190,7 @@ static inline int RichString_writeFromWide(RichString* this, int attrs, const ch
    }
    this->chptr[newLen] = 0;
 
-   return len;
+   return (int)len;
 }
 
 int RichString_appendnWideColumns(RichString* this, int attrs, const char* data_c, size_t len, int* columns) {
diff --git a/linux/LibSensors.c b/linux/LibSensors.c
index e4e924be8..55ebcf6af 100644
--- a/linux/LibSensors.c
+++ b/linux/LibSensors.c
@@ -206,6 +206,14 @@ int LibSensors_countCCDs(void) {
    return ccds;
 }
 
+static int LibSensors_stringToID(const char* str) {
+   char* endptr;
+   unsigned long parsedID = strtoul(str, &endptr, 10);
+   if (parsedID >= INT_MAX || *endptr != '\0')
+      return -1;
+   return (int)parsedID;
+}
+
 void LibSensors_getCPUTemperatures(CPUData* cpus, unsigned int existingCPUs, unsigned int activeCPUs) {
    assert(existingCPUs > 0 && existingCPUs < 16384);
 
@@ -344,17 +352,21 @@ void LibSensors_getCPUTemperatures(CPUData* cpus, unsigned int existingCPUs, uns
          char *label = sym_sensors_get_label(chip, feature);
          if (label) {
             bool skip = true;
+            int ID;
             /* Intel coretemp names, labels mention package and physical id */
             if (String_startsWith(label, "Package id ")) {
-               physicalID = strtoul(label + strlen("Package id "), NULL, 10);
+               if ((ID = LibSensors_stringToID(label + strlen("Package id "))) != -1)
+                  physicalID = ID;
             } else if (String_startsWith(label, "Physical id ")) {
-               physicalID = strtoul(label + strlen("Physical id "), NULL, 10);
+               if ((ID = LibSensors_stringToID(label + strlen("Physical id "))) != -1)
+                  physicalID = ID;
             } else if (String_startsWith(label, "Core ")) {
-               int coreID = strtoul(label + strlen("Core "), NULL, 10);
-               for (size_t i = 1; i < existingCPUs + 1; i++) {
-                  if (cpus[i].physicalID == physicalID && cpus[i].coreID == coreID) {
-                     data[i] = temp;
-                     coreTempCount++;
+               if ((ID = LibSensors_stringToID(label + strlen("Core "))) != -1) {
+                  for (size_t i = 1; i < existingCPUs + 1; i++) {
+                     if (cpus[i].physicalID == physicalID && cpus[i].coreID == ID) {
+                        data[i] = temp;
+                        coreTempCount++;
+                     }
                   }
                }
             }
diff --git a/linux/LinuxProcessTable.c b/linux/LinuxProcessTable.c
index 7aca7383e..3b07b5869 100644
--- a/linux/LinuxProcessTable.c
+++ b/linux/LinuxProcessTable.c
@@ -77,6 +77,14 @@ static FILE* fopenat(openat_arg_t openatArg, const char* pathname, const char* m
    return fp;
 }
 
+static pid_t strtopid(const char* str) {
+   char* endptr;
+   unsigned long parsedPid = strtoul(str, &endptr, 10);
+   if (parsedPid == 0 || parsedPid >= INT_MAX || *endptr != '\0')
+      return 0; // indicate failure by an invalid pid
+   return (pid_t)parsedPid;
+}
+
 static inline uint64_t fast_strtoull_dec(char** str, size_t maxlen) {
    uint64_t result = 0;
 
@@ -982,8 +990,8 @@ static void LinuxProcessTable_readOpenVZData(LinuxProcess* process, openat_arg_t
                free_and_xStrdup(&process->ctid, name_value_sep);
             break;
          case 2:
-            foundVPid = true;
-            process->vpid = strtoul(name_value_sep, NULL, 0);
+            if ((process->vpid = strtopid(name_value_sep)) != 0)
+               foundVPid = true;
             break;
          default:
             //Sanity Check: Should never reach here, or the implementation is missing something!
@@ -1582,14 +1590,9 @@ static bool LinuxProcessTable_recurseProcTree(LinuxProcessTable* this, openat_ar
       }
 
       // filename is a number: process directory
-      int pid;
-      {
-         char* endptr;
-         unsigned long parsedPid = strtoul(name, &endptr, 10);
-         if (parsedPid == 0 || parsedPid >= INT_MAX || *endptr != '\0')
-            continue;
-         pid = (int)parsedPid;
-      }
+      pid_t pid = strtopid(name);
+      if (pid == 0)
+         continue;
 
       // Skip task directory of main thread
       if (mainTask && pid == Process_getPid(&mainTask->super))