diff --git a/mainwindow.cpp b/mainwindow.cpp
index 451ba5321..9cebdf704 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1188,7 +1188,7 @@ void MainWindow::readFromStdout()                             //readFromStdout
       ui->decodedTextBrowser->setTextCursor(cursor);
 
       QString msg=t.mid(34,22);
-      bool b=stdmsg_(msg.toAscii().constData());
+      bool b=stdmsg_(msg.toAscii().constData(),22);
       QStringList w=msg.split(" ",QString::SkipEmptyParts);
       if(b and w[0]==m_myCall) {
         QString tt=w[2];
diff --git a/mainwindow.h b/mainwindow.h
index 747ce365f..d8ceaedea 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -306,7 +306,7 @@ void symspec_(int* k, int* ntrperiod, int* nsps, int* ingain, int* nb,
 void genjt9_(char* msg, int* ichk, char* msgsent, int itone[],
              int* itext, int len1, int len2);
 
-bool stdmsg_(const char* msg);
+bool stdmsg_(const char* msg, int len);
 
 void azdist_(char* MyGrid, char* HisGrid, double* utch, int* nAz, int* nEl,
              int* nDmiles, int* nDkm, int* nHotAz, int* nHotABetter,