diff --git a/config.h.in b/config.h.in
index 509bbae54..70e33e52e 100755
--- a/config.h.in
+++ b/config.h.in
@@ -77,7 +77,6 @@ typedef  int          ftnlen;       // Fortran hidden string length type
 // Identify whether the operating system is solaris 
 // with a native compiler 
 #undef SOLARIS
-o
 
 //--------- Fonts for reaction path diagrams ----------------------
 #undef RXNPATH_FONT