diff --git a/cil-1.7.3-bytecode-compilation.patch b/cil-1.7.3-bytecode-compilation.patch
new file mode 100644
index 0000000..3b4694a
--- /dev/null
+++ b/cil-1.7.3-bytecode-compilation.patch
@@ -0,0 +1,11 @@
+--- cil-1.7.3/myocamlbuild.ml.orig	2015-07-20 12:56:57.224597528 +0100
++++ cil-1.7.3/myocamlbuild.ml	2015-07-20 12:57:04.742605963 +0100
+@@ -8,7 +8,7 @@
+   let dirs = include_dirs_of (dirname mllib) in
+   let modules = string_list_of_file mllib in
+   let make_candidates m =
+-    List.map (expand_module dirs m) [["cmi"]; ["cmx"]; ["mli"; "inferred.mli"]] in
++    List.map (expand_module dirs m) [["cmi"]; ["cmo"]; ["mli"; "inferred.mli"]] in
+   let dependencies = List.flatten (List.map make_candidates modules) in
+   let build_result = builder dependencies in
+   let built_files = List.filter_opt
diff --git a/ocaml-cil.spec b/ocaml-cil.spec
index 839cef9..8d9d920 100644
--- a/ocaml-cil.spec
+++ b/ocaml-cil.spec
@@ -2,15 +2,13 @@
 
 Name:           ocaml-cil
 Version:        1.7.3
-Release:        21%{?dist}
+Release:        22%{?dist}
 Summary:        CIL - Infrastructure for C Program Analysis and Transformation
 License:        BSD
 
 URL:            http://cil.sourceforge.net/
 Source0:        http://downloads.sourceforge.net/cil/cil-%{version}.tar.gz
 
-ExcludeArch:    sparc64 s390 s390x
-
 BuildRequires:  ocaml, ocaml-findlib-devel, ocaml-ocamldoc
 
 Patch0:         0001-Fix-testsuite-on-32-bit-machines.patch
@@ -27,6 +25,9 @@ Patch3:         cil-1.7.3-add-package-cilconfig.patch
 # https://bugzilla.redhat.com/show_bug.cgi?id=1120273
 Patch4:         ocaml-4.02.0.patch
 
+# Fix for bytecode compilation (only apply this when !opt).
+Patch5:         cil-1.7.3-bytecode-compilation.patch
+
 %description
 CIL (C Intermediate Language) is a high-level representation along
 with a set of tools that permit easy analysis and source-to-source
@@ -109,6 +110,9 @@ for gcc.
 %patch2 -p1
 %patch3 -p1
 %patch4 -p1
+%if !%opt
+%patch5 -p1
+%endif
 
 %build
 
@@ -184,6 +188,9 @@ rm -rf $RPM_BUILD_ROOT
 
 
 %changelog
+* Mon Jul 20 2015 Richard W.M. Jones <rjones@redhat.com> 1.7.3-22
+- Add patch for bytecode compilation, and enable on all arches.
+
 * Mon Jun 29 2015 Peter Robinson <pbrobinson@fedoraproject.org> 1.7.3-21
 - Build on ARMv7 (rhbz 994968) as it seems to now be fixed