diff --git a/Cantera/src/Makefile.in b/Cantera/src/Makefile.in
index 9d210be65..9610e030c 100755
--- a/Cantera/src/Makefile.in
+++ b/Cantera/src/Makefile.in
@@ -76,8 +76,8 @@ rpath: $(RPATH)
 
 solvers: $(SOLVERS)
 
-#tpx: 
-#	cd $(EXT)/tpx; @MAKE@
+tpx: 
+	cd $(EXT)/tpx; @MAKE@
 
 flow1D:
 	cd oneD;  @MAKE@