diff --git a/_constraints b/_constraints
index 4b2c103..839950a 100644
--- a/_constraints
+++ b/_constraints
@@ -1,7 +1,7 @@
 <constraints>
  <hardware>
   <memory>
-   <size unit="G">4</size>
+   <size unit="G">5</size>
   </memory>
  </hardware>
-</constraints>
\ No newline at end of file
+</constraints>
diff --git a/gnuradio.changes b/gnuradio.changes
index ee008ae..5d20484 100644
--- a/gnuradio.changes
+++ b/gnuradio.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Sep  9 08:06:26 UTC 2014 - coolo@suse.com
+
+- disable parallal build - it's too unreliable (due to memory pressure
+  on OBS workers)
+
 -------------------------------------------------------------------
 Thu Aug 28 14:20:37 UTC 2014 - dmitry_r@opensuse.org
 
diff --git a/gnuradio.spec b/gnuradio.spec
index b56c27c..5b73f2d 100644
--- a/gnuradio.spec
+++ b/gnuradio.spec
@@ -143,7 +143,7 @@ sed -i 's|^HTML_TIMESTAMP         = YES|HTML_TIMESTAMP         = NO|' docs/doxyg
 %build
 %cmake \
       -DCMAKE_SHARED_LINKER_FLAGS=""
-make %{?_smp_mflags}
+make -j1
 
 %install
 %cmake_install