diff --git a/dynare++/integ/cc/main.web b/dynare++/integ/cc/main.web
index f2a4009ee..c5209b24c 100644
--- a/dynare++/integ/cc/main.web
+++ b/dynare++/integ/cc/main.web
@@ -1,8 +1,14 @@
 @q $Id: main.web 2333 2009-01-14 10:32:55Z kamenik $ @>
 @q Copyright 2005, Ondra Kamenik @>
 
+@q cwebmac.tex defines its own \ifpdf, which is incompatible with the \ifpdf defined by eplain, so undefine it @>
 \let\ifpdf\relax
 \input eplain
+
+@q now define \ifpdf to be always false: PDF macros of cwebmac are buggy @>
+\newif\ifpdf
+\iffalse\fi
+
 \def\title{{\mainfont Numerical Integration Module}}
 
 
diff --git a/dynare++/kord/main.web b/dynare++/kord/main.web
index 118e393a9..aebd8eea9 100644
--- a/dynare++/kord/main.web
+++ b/dynare++/kord/main.web
@@ -1,8 +1,14 @@
 @q $Id: main.web 2333 2009-01-14 10:32:55Z kamenik $ @>
 @q Copyright 2004, Ondra Kamenik @>
 
+@q cwebmac.tex defines its own \ifpdf, which is incompatible with the \ifpdf defined by eplain, so undefine it @>
 \let\ifpdf\relax
 \input eplain
+
+@q now define \ifpdf to be always false: PDF macros of cwebmac are buggy @>
+\newif\ifpdf
+\iffalse\fi
+
 \def\title{{\mainfont Dynare++}}
 
 
diff --git a/dynare++/tl/cc/main.web b/dynare++/tl/cc/main.web
index 599a70db9..13935d7e9 100644
--- a/dynare++/tl/cc/main.web
+++ b/dynare++/tl/cc/main.web
@@ -1,8 +1,14 @@
 @q $Id: main.web 2338 2009-01-14 10:40:30Z kamenik $ @>
 @q Copyright 2004, Ondra Kamenik @>
 
+@q cwebmac.tex defines its own \ifpdf, which is incompatible with the \ifpdf defined by eplain, so undefine it @>
 \let\ifpdf\relax
 \input eplain
+
+@q now define \ifpdf to be always false: PDF macros of cwebmac are buggy @>
+\newif\ifpdf
+\iffalse\fi
+
 \def\title{{\mainfont Tensor Library}}