diff --git a/ghc.spec b/ghc.spec
index 73b3ba8..0176b13 100644
--- a/ghc.spec
+++ b/ghc.spec
@@ -144,10 +144,9 @@ export CFLAGS="${CFLAGS:-%optflags}"
   %{?with_shared:--enable-shared}
 
 # 4 cpus or more sometimes breaks build
-RPM_BUILD_NCPUS=$(/usr/bin/getconf _NPROCESSORS_ONLN)
-[ "$RPM_BUILD_NCPUS" -gt 2 ] && RPM_BUILD_NCPUS=2
-export RPM_BUILD_NCPUS
-make %{_smp_mflags}
+[ -z "$RPM_BUILD_NCPUS" ] && RPM_BUILD_NCPUS=$(/usr/bin/getconf _NPROCESSORS_ONLN)
+[ "$RPM_BUILD_NCPUS" -gt 4 ] && RPM_BUILD_NCPUS=4
+make -j$RPM_BUILD_NCPUS
 
 %install
 rm -rf $RPM_BUILD_ROOT
@@ -283,7 +282,7 @@ fi
 * Thu Sep 30 2010 Jens Petersen <petersen@redhat.com> - 6.12.3-6
 - move gtk2hs obsoletes to ghc-glib and ghc-gtk
 - drop happy buildrequires
-- smp build with max 2 cpus
+- smp build with max 4 cpus
 
 * Fri Jul 30 2010 Jens Petersen <petersen@redhat.com> - 6.12.3-5
 - obsolete old gtk2hs packages for smooth upgrades