diff --git a/_constraints b/_constraints
index 3af2077..4e330b3 100644
--- a/_constraints
+++ b/_constraints
@@ -7,8 +7,11 @@
     </conditions>
     <hardware>
       <physicalmemory>
-        <size unit="G">10</size>
+        <size unit="G">6</size>
       </physicalmemory>
+      <memory>
+        <size unit="G">10</size>
+      </memory>
     </hardware>
   </overwrite>
 
@@ -18,6 +21,9 @@
       <disk>
         <size unit="G">13</size>
       </disk>
+      <memory>
+        <size unit="G">8</size>
+      </memory>
     </hardware>
   </overwrite>
 </constraints>
diff --git a/mariadb.changes b/mariadb.changes
index 3361ff9..73b5c1d 100644
--- a/mariadb.changes
+++ b/mariadb.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Thu Sep  5 21:43:14 UTC 2019 - Stefan Brüns <stefan.bruens@rwth-aachen.de>
+
+- Use <memory> instead of <physicalmemory> for _constraints, increasing
+  the worker pool on x86_64 from 6 to >700.
+
 -------------------------------------------------------------------
 Thu Aug  8 10:06:04 UTC 2019 - Kristyna Streitova <kstreitova@suse.com>