diff --git a/src/lib/support/StringBuilder.cpp b/src/lib/support/StringBuilder.cpp
index 8143f95237d4c2..44c7a8004ffb82 100644
--- a/src/lib/support/StringBuilder.cpp
+++ b/src/lib/support/StringBuilder.cpp
@@ -28,6 +28,8 @@ StringBuilderBase & StringBuilderBase::AddFormat(const char * format, ...)
     if (mWriter.Available() > 0)
     {
         output = reinterpret_cast<char *>(mWriter.Buffer() + mWriter.Needed());
+    } else {
+        output = reinterpret_cast<char *>(mWriter.Buffer() + mWriter.Size());
     }
 
     // the + 1 size here because StringBuilder reserves one byte for final null terminator