diff --git a/lib/charbuf.cpp b/lib/charbuf.cpp
index 20281992..5d3efc3e 100755
--- a/lib/charbuf.cpp
+++ b/lib/charbuf.cpp
@@ -217,6 +217,10 @@ void CharBuffer::Append(const char* source)
 
 bool CharBuffer::RemoveTrailing(const char c)
 {
+    if (ptr == buf) {
+        return false;
+    }
+
     if (*(ptr - 1) == c) {
         ptr--;
         return true;