diff --git a/src/generic/logg.cpp b/src/generic/logg.cpp
index 1b7301174b..4a6598ba41 100644
--- a/src/generic/logg.cpp
+++ b/src/generic/logg.cpp
@@ -340,6 +340,7 @@ wxLogGui::DoShowMultipleLogMessages(const wxArrayString& messages,
 #else // !wxUSE_LOG_DIALOG
     // start from the most recent message
     wxString message;
+    const size_t nMsgCount = messages.size();
     str.reserve(nMsgCount*100);
     for ( size_t n = nMsgCount; n > 0; n-- ) {
         message << m_aMessages[n - 1] << wxT("\n");