diff --git a/PrusaSlicer.changes b/PrusaSlicer.changes
index 26cddb4..cd7ce02 100644
--- a/PrusaSlicer.changes
+++ b/PrusaSlicer.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Thu Aug 20 09:03:33 UTC 2020 - Martin Liška <mliska@suse.cz>
+
+- Use memoryperjob constraint instead of %limit_build macro.
+- Use only 1GB for memoryperjob.
+
 -------------------------------------------------------------------
 Mon Aug 10 08:12:10 UTC 2020 - Stefan Brüns <stefan.bruens@rwth-aachen.de>
 
diff --git a/PrusaSlicer.spec b/PrusaSlicer.spec
index a0b4983..fe305f2 100644
--- a/PrusaSlicer.spec
+++ b/PrusaSlicer.spec
@@ -45,7 +45,6 @@ BuildRequires:  libboost_system-devel
 BuildRequires:  libboost_thread-devel
 BuildRequires:  libcurl-devel
 BuildRequires:  libexpat-devel
-BuildRequires:  memory-constraints
 BuildRequires:  nlopt-devel
 BuildRequires:  openvdb-devel >= 5
 BuildRequires:  openvdb-tools
@@ -67,7 +66,6 @@ It also works with Mach3, LinuxCNC and Machinekit controllers.
 sed -i 's/UNKNOWN/OpenSUSE/' version.inc
 
 %build
-%limit_build -m 4096
 # sse2 flags for 32-bit: see gh#prusa3d/PrusaSlicer#3781 
 %ifarch %ix86
   export CFLAGS="%optflags -mfpmath=sse -msse2"
diff --git a/_constraints b/_constraints
index cbb4c6b..6881d1d 100644
--- a/_constraints
+++ b/_constraints
@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <constraints>
   <hardware>
     <disk>
@@ -6,5 +7,8 @@
     <memory>
       <size unit="G">8</size>
     </memory>
+    <memoryperjob>
+      <size unit="M">1024</size>
+    </memoryperjob>
   </hardware>
 </constraints>