diff --git a/clufter.spec b/clufter.spec
index 15338ca..fed671d 100644
--- a/clufter.spec
+++ b/clufter.spec
@@ -11,7 +11,7 @@
 
 Name:           clufter
 Version:        0.77.1
-Release:        5%{?dist}
+Release:        6%{?dist}
 Summary:        Tool/library for transforming/analyzing cluster configuration formats
 License:        GPLv2+
 URL:            https://pagure.io/%{name}
@@ -303,11 +303,21 @@ mv -t '%{buildroot}%{_datarootdir}/%{name}/ext-plugins' \
 
 # byte-compilation
 %if %{with python2}
-%py_byte_compile '%{__python2} \-Es' '%{python2_sitelib}/%{name}'
-%py_byte_compile '%{__python2} \-Es' '%{buildroot}%{_datarootdir}/%{name}/ext-plugins'
+%if "%{?quote:1}" != "" && "%{?quote:1}" != "1"
+%py_byte_compile %{quote:%{__python2} -Es} %{python2_sitelib}/%{name}
+%py_byte_compile %{quote:%{__python2} -Es} %{buildroot}%{_datarootdir}/%{name}/ext-plugins
+%else
+%py_byte_compile %{__python2} %{python2_sitelib}/%{name}
+%py_byte_compile %{__python2} %{buildroot}%{_datarootdir}/%{name}/ext-plugins
+%endif
+%endif
+%if "%{?quote:1}" != "" && "%{?quote:1}" != "1"
+%py_byte_compile %{quote:%{__python3} -I} %{python3_sitelib}/%{name}
+%py_byte_compile %{quote:%{__python3} -I} %{buildroot}%{_datarootdir}/%{name}/ext-plugins
+%else
+%py_byte_compile %{__python3} %{python3_sitelib}/%{name}
+%py_byte_compile %{__python3} %{buildroot}%{_datarootdir}/%{name}/ext-plugins
 %endif
-%py_byte_compile '%{__python3} \-I' '%{python3_sitelib}/%{name}'
-%py_byte_compile '%{__python3} \-I' '%{buildroot}%{_datarootdir}/%{name}/ext-plugins'
 
 declare bashcompdir="$(pkg-config --variable=completionsdir bash-completion \
                        || echo '%{_datadir}/bash-completion/completions')"
@@ -415,6 +425,13 @@ test -x '%{_bindir}/%{name}' && test -f "${bashcomp}" \
 %{_datarootdir}/%{name}/ext-plugins/lib-pcs
 
 %changelog
+* Thu Aug 02 2018 Jan Pokorný <jpokorny+rpm-clufter@fedoraproject.org> - 0.77.1-6
+- fix missing explicit BuildRequires to ensure environment for compiling
+  C code per the guidelines, and to fix FTBFS: rhbz#1603658
+  (contributed by Igor Gnatenko <ignatenkobrain@fedoraproject.org>)
+- fix a thinko in py_byte_compile space-contained argument passing
+  (https://github.com/rpm-software-management/rpm/issues/222#issuecomment-410026431)
+
 * Thu Jul 12 2018 Fedora Release Engineering <releng@fedoraproject.org> - 0.77.1-5
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass_Rebuild