diff --git a/doc/bvar-a-la-sims.tex b/doc/bvar-a-la-sims.tex
index f910515ca..007101dc9 100644
--- a/doc/bvar-a-la-sims.tex
+++ b/doc/bvar-a-la-sims.tex
@@ -545,7 +545,7 @@ Most results are stored for future use:
 The syntax for computing impulse response functions is:
 
 \medskip
-\texttt{bvar\_irf(}\textit{number\_of\_lags},\textit{identification\_scheme}\texttt{);}
+\texttt{bvar\_irf(}\textit{number\_of\_periods},\textit{identification\_scheme}\texttt{);}
 \medskip
 
 The \textit{identification\_scheme} option has two potential values