diff --git a/configure.in b/configure.in
index 6575a3a..411db24 100644
--- a/configure.in
+++ b/configure.in
@@ -6,6 +6,7 @@ AM_INIT_AUTOMAKE(tclap,1.0.3)
 AC_PROG_CXX
 AC_CXX_HAVE_SSTREAM
 AC_CXX_HAVE_STRSTREAM
+AC_CHECK_PROG(DOT,dot,YES,NO)
 AC_PROG_RANLIB
 AC_PROG_INSTALL
 BB_ENABLE_DOXYGEN
diff --git a/docs/Doxyfile.in b/docs/Doxyfile.in
index ce94a19..ce56856 100644
--- a/docs/Doxyfile.in
+++ b/docs/Doxyfile.in
@@ -958,7 +958,7 @@ HIDE_UNDOC_RELATIONS   = YES
 # toolkit from AT&T and Lucent Bell Labs. The other options in this section 
 # have no effect if this option is set to NO (the default)
 
-HAVE_DOT               = YES
+HAVE_DOT               = @DOT@
 
 # If the CLASS_GRAPH and HAVE_DOT tags are set to YES then doxygen 
 # will generate a graph for each documented class showing the direct and