diff --git a/PowerEditor/src/NppNotification.cpp b/PowerEditor/src/NppNotification.cpp
index 784e5e9d7..5bb5c4d96 100644
--- a/PowerEditor/src/NppNotification.cpp
+++ b/PowerEditor/src/NppNotification.cpp
@@ -752,6 +752,9 @@ BOOL Notepad_plus::notify(SCNotification *notification)
 					// which are closest to the clicked position.
 					for (int32_t i = static_cast<int32_t>(position_of_click); i >= 0; --i)
 					{
+						if (i >= static_cast<int32_t>(bufstring.size()))
+							return FALSE;
+
 						if (bufstring.at(i) == nppGUI._leftmostDelimiter)
 						{
 							// Respect escaped quotation marks.