diff --git a/Doc/lib/libmath.tex b/Doc/lib/libmath.tex
index 1dc43655fa1..0571b18fdd1 100644
--- a/Doc/lib/libmath.tex
+++ b/Doc/lib/libmath.tex
@@ -87,8 +87,8 @@ Return \code{\var{x} * (2**\var{i})}.
 \end{funcdesc}
 
 \begin{funcdesc}{log}{x\optional{, base}}
-Returns the logarithm of \var{x} to the given base.
-If the base is not specified, returns the natural logarithm of \var{x}.
+Returns the logarithm of \var{x} to the given \var{base}.
+If the \var{base} is not specified, returns the natural logarithm of \var{x}.
 \versionchanged[\var{base} argument added]{2.3}
 \end{funcdesc}