diff --git a/src/NimBLEAdvertising.cpp b/src/NimBLEAdvertising.cpp
index af98b34..4dd5a39 100644
--- a/src/NimBLEAdvertising.cpp
+++ b/src/NimBLEAdvertising.cpp
@@ -138,7 +138,7 @@ void NimBLEAdvertising::addTxPower() {
  */
 void NimBLEAdvertising::setName(const std::string &name) {
     m_name.assign(name.begin(), name.end());
-    m_name[name.length()] = 0;
+    if (name.length() <= 19) m_name[name.length()] = 0;
     m_advData.name = &m_name[0];
     m_advData.name_len = m_name.size();
     m_advDataSet = false;