diff --git a/gnuradio.spec b/gnuradio.spec
index 620b040..961607b 100644
--- a/gnuradio.spec
+++ b/gnuradio.spec
@@ -48,11 +48,11 @@ BuildRequires:	portaudio-devel, libtool, gsm-devel
 # http://gnuradio.org/redmine/issues/show/395
 # BuildRequires: comedilib-devel
 BuildRequires:	gsl-devel, tex(latex), numpy, PyQt4-devel, python2-cheetah
-BuildRequires:	xdg-utils, python2-lxml, pygtk2-devel
+BuildRequires:	xdg-utils, python2-lxml, pygtk2-devel, orc-devel
 BuildRequires:	desktop-file-utils, python2-mako, python2-six
 BuildRequires:	uhd-devel, python2, cppzmq-devel, zeromq-devel, thrift
-BuildRequires:	python2-sphinx, codec2-devel, sphinx, jack-devel
-BuildRequires:	comedilib-devel
+BuildRequires:	python2-sphinx, codec2-devel, findutils
+BuildRequires:	comedilib-devel, jack-audio-connection-kit-devel
 #BuildRequires:	python3-thrift
 %if ! 0%{?rhel:1}
 BuildRequires:	PyQwt-devel, qwt-devel, qwtplot3d-qt4-devel
@@ -119,14 +119,11 @@ cd build
 %cmake \
 -DSYSCONFDIR=%{_sysconfdir} \
 -DGR_PKG_DOC_DIR=%{_docdir}/%{name} \
+-DENABLE_DOXYGEN=FALSE \
 %{?mfpu_neon} \
 ..
 
-# make with -j2 to prevent internal compiler errors due to excessive
-# use of resources
-make -j2 CFLAGS="%{optflags} -fno-strict-aliasing" CXXFLAGS="%{optflags} -fno-strict-aliasing"
-
-#make %{?_smp_mflags} CFLAGS="%{optflags} -fno-strict-aliasing" CXXFLAGS="%{optflags} -fno-strict-aliasing"
+make %{?_smp_mflags} CFLAGS="%{optflags} -fno-strict-aliasing" CXXFLAGS="%{optflags} -fno-strict-aliasing"
 
 %install
 rm -rf %{buildroot}
@@ -154,6 +151,11 @@ done
 rm -f %{buildroot}%{_datadir}/%{name}/grc/freedesktop/*
 rmdir %{buildroot}%{_datadir}/%{name}/grc/freedesktop
 
+# fix hashbangs
+pushd %{buildroot}%{_bindir}
+sed -i '1 s/^\(#!\/usr\/bin\/\)\(env\|python\).*$/\1python2/' gr-ctrlport-monitor gr-perf-monitorx
+popd
+
 %post -p /sbin/ldconfig
 
 %postun -p /sbin/ldconfig
@@ -194,6 +196,11 @@ rmdir %{buildroot}%{_datadir}/%{name}/grc/freedesktop
   Resolves: rhbz#1608973
 - Enabled ZeroMQ, sphinx, comedilib, jack, and log4cpp
   Resolves: rhbz#1610513
+- Temporaly disabled doxygen (the doc subpackage is mostly useless now),
+  because due to various bugs in different packages the documentation builds
+  differently on different architectures
+- Fixed python hashbangs
+- Unlimited number of make processes
 
 * Sun Jul 22 2018 Jaroslav Škarvada <jskarvad@redhat.com> - 3.7.13.4-2
 - Rebuilt for new uhd