diff --git a/obuild-arg-parsing.patch b/obuild-arg-parsing.patch
new file mode 100644
index 0000000..b5b0964
--- /dev/null
+++ b/obuild-arg-parsing.patch
@@ -0,0 +1,34 @@
+From 6bdda41644e9b5e5dd059885a0f3bacdfa946f9a Mon Sep 17 00:00:00 2001
+From: Andy Li <andy@onthewings.net>
+Date: Sun, 19 Nov 2017 21:26:07 +0800
+Subject: [PATCH] do not call set_target_options when just parsing -g -pg
+
+---
+ src/main.ml | 14 ++++++++------
+ 1 file changed, 8 insertions(+), 6 deletions(-)
+
+diff --git a/src/main.ml b/src/main.ml
+index 67fd4b0..cae01d8 100644
+--- a/src/main.ml
++++ b/src/main.ml
+@@ -42,12 +42,14 @@ let configure argv =
+     ("--flag", Arg.String user_set_flags, "enable or disable a project's flag");
+     ("--executable-as-obj", Arg.Unit (set_target_options "executable-as-obj" true), "output executable as obj file");
+     ("--annot", Arg.Unit (set_target_options "annot" true), "generate .annot files");
+-    ("-g", Arg.Unit (
+-        (set_target_options "library-debugging" true) ();
+-        (set_target_options "executable-debugging" true)), "compilation with debugging");
+-    ("-pg", Arg.Unit (
+-        (set_target_options "library-profiling" true) ();
+-        (set_target_options "executable-profiling" true)), "compilation with profiling")
++    ("-g", Arg.Unit (fun () ->
++        (set_target_options "library-debugging" true)();
++        (set_target_options "executable-debugging" true)();
++    ), "compilation with debugging");
++    ("-pg", Arg.Unit (fun () ->
++        (set_target_options "library-profiling" true)();
++        (set_target_options "executable-profiling" true)();
++    ), "compilation with profiling")
+   ] in
+   Arg.parse_argv (Array.of_list argv) (
+     enable_disable_opt "library-bytecode" "library compilation as bytecode"
diff --git a/ocaml-obuild.spec b/ocaml-obuild.spec
index c7d4f6e..1a6bbca 100644
--- a/ocaml-obuild.spec
+++ b/ocaml-obuild.spec
@@ -9,6 +9,9 @@ License:        BSD
 URL:            https://github.com/ocaml-obuild/obuild
 Source0:        https://github.com/ocaml-obuild/obuild/archive/obuild-v%{version}/%{name}-%{version}.tar.gz
 
+# https://github.com/ocaml-obuild/obuild/issues/169
+Patch0:         obuild-arg-parsing.patch
+
 BuildRequires:  ocaml
 BuildRequires:  help2man
 
@@ -27,6 +30,7 @@ way of working, adapting parts where necessary to fully support OCaml.
 
 %prep
 %setup -q -n obuild-obuild-v%{version}
+%patch0 -p1
 
 
 %build