diff --git a/threaddata.cpp b/threaddata.cpp
index b1ed210..45cb9cd 100644
--- a/threaddata.cpp
+++ b/threaddata.cpp
@@ -49,7 +49,8 @@ void ThreadData::start(thread_f f)
     std::ostringstream threadName;
     threadName << "FlashMQ T " << threadnr;
     threadName.flush();
-    const char *c_str = threadName.str().c_str();
+    std::string name = threadName.str();
+    const char *c_str = name.c_str();
     pthread_setname_np(native, c_str);
 
     cpu_set_t cpuset;
diff --git a/utils.cpp b/utils.cpp
index 3e525de..f970b69 100644
--- a/utils.cpp
+++ b/utils.cpp
@@ -261,7 +261,7 @@ int64_t currentMSecsSinceEpoch()
 
 std::string getSecureRandomString(const ssize_t len)
 {
-    std::vector<char> buf(len);
+    std::vector<unsigned char> buf(len);
     ssize_t actual_len = getrandom(buf.data(), len, 0);
 
     if (actual_len < 0 || actual_len != len)
@@ -273,7 +273,7 @@ std::string getSecureRandomString(const ssize_t len)
     const int possibleCharactersCount = possibleCharacters.length();
 
     std::string randomString;
-    for(const unsigned char &c : buf)
+    for(const unsigned char c : buf)
     {
         unsigned int index = c % possibleCharactersCount;
         char nextChar = possibleCharacters.at(index);