diff --git a/ocaml-labltk.spec b/ocaml-labltk.spec
index 975f6a3..94496a5 100644
--- a/ocaml-labltk.spec
+++ b/ocaml-labltk.spec
@@ -6,7 +6,7 @@
 
 Name:          ocaml-labltk
 Version:       8.06.0
-Release:       3%{?dist}
+Release:       4%{?dist}
 
 Summary:       Tcl/Tk interface for OCaml
 
@@ -67,9 +67,11 @@ make install \
     BINDIR=$RPM_BUILD_ROOT%{_bindir} \
     INSTALLDIR=$RPM_BUILD_ROOT%{_libdir}/ocaml/labltk \
     STUBLIBDIR=$RPM_BUILD_ROOT%{_libdir}/ocaml/stublibs
+%if %{native_compiler}
 # The *.o files are not installed by the Makefile.  AIUI
 # that prevents linking with native code programs.
 install -m 0644 camltk/*.o $RPM_BUILD_ROOT%{_libdir}/ocaml/labltk
+%endif
 
 
 %files
@@ -100,6 +102,9 @@ install -m 0644 camltk/*.o $RPM_BUILD_ROOT%{_libdir}/ocaml/labltk
 
 
 %changelog
+* Wed Jul 22 2015 Richard W.M. Jones <rjones@redhat.com> - 8.06.0-4
+- s390x: Don't copy *.o files when building bytecode.
+
 * Wed Jun 24 2015 Richard W.M. Jones <rjones@redhat.com> - 8.06.0-3
 - ocaml-4.02.2 final rebuild.