diff --git a/Cantera/src/Makefile.in b/Cantera/src/Makefile.in
index 49f1a773c..6e0dd6af9 100755
--- a/Cantera/src/Makefile.in
+++ b/Cantera/src/Makefile.in
@@ -13,7 +13,8 @@
 
 OBJDIR = .
 
-CXX_FLAGS = @CXXFLAGS@ $(CXX_OPT)
+# LOCAL_DEFNS=-DDEBUG_PATHS
+CXX_FLAGS = @CXXFLAGS@ $(CXX_OPT) $(LOCAL_DEFNS)
 
 EXT        = ../../ext