diff --git a/src/cppipe.cpp b/src/cppipe.cpp
index b845b74..9f5a50f 100644
--- a/src/cppipe.cpp
+++ b/src/cppipe.cpp
@@ -197,8 +197,8 @@ bool preprocess_and_compare()
 	Cmd preprocess(
 		CXX,
 		"-E",		// preprocess only
-		"-P",		// don't generate linemarkers in the output to reduce file size
-		src_file.c_str()
+		src_file.c_str(),
+		CXXFLAGS
 		);
 	if(!debug)
 		preprocess +=  "-DNDEBUG";
diff --git a/todo.txt b/todo.txt
index b54a637..982460b 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,4 +1,5 @@
 support C
+github
 man
 .cppipe file extension
 tips