diff --git a/MozillaFirefox.changes b/MozillaFirefox.changes
index 33b2fc5..6fc6506 100644
--- a/MozillaFirefox.changes
+++ b/MozillaFirefox.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Thu Aug 20 13:07:33 UTC 2020 - Martin Liška <mliska@suse.cz>
+
+- Use new memoryperjob _constraints instead of %limit_build macro.
+
 -------------------------------------------------------------------
 Mon Aug 10 09:19:38 UTC 2020 - Wolfgang Rosenauer <wr@rosenauer.org>
 
diff --git a/MozillaFirefox.spec b/MozillaFirefox.spec
index 4c54f75..f7d7993 100644
--- a/MozillaFirefox.spec
+++ b/MozillaFirefox.spec
@@ -82,7 +82,6 @@ BuildRequires:  autoconf213
 BuildRequires:  dbus-1-glib-devel
 BuildRequires:  dejavu-fonts
 BuildRequires:  fdupes
-BuildRequires:  memory-constraints
 %if 0%{?suse_version} <= 1320
 BuildRequires:  gcc9-c++
 %else
@@ -430,11 +429,6 @@ echo "export MOZ_TELEMETRY_REPORTING=1"
 echo ""
 cat << EOF
 %else
-%ifarch ppc64 ppc64le
-%limit_build -m 2500
-%else
-%limit_build -m 2000
-%endif
 cat << EOF > $MOZCONFIG
 %endif
 mk_add_options MOZILLA_OFFICIAL=1
diff --git a/_constraints b/_constraints
index 443eb28..8c6fedd 100644
--- a/_constraints
+++ b/_constraints
@@ -7,6 +7,9 @@
     <memory>
       <size unit="G">8</size>
     </memory>
+    <memoryperjob>
+      <size unit="M">2000</size>
+    </memoryperjob>
   </hardware>
   <overwrite>
     <conditions>
@@ -54,6 +57,9 @@
       <physicalmemory>
         <size unit="G">10</size>
       </physicalmemory>
+      <memoryperjob>
+        <size unit="M">2500</size>
+      </memoryperjob>
     </hardware>
   </overwrite>
 </constraints>