diff --git a/source-builder/sb/linux.py b/source-builder/sb/linux.py
index 22973f8..7e01149 100644
--- a/source-builder/sb/linux.py
+++ b/source-builder/sb/linux.py
@@ -43,7 +43,7 @@ def load():
                 if count > cpus:
                     cpus = int(count)
             if cpus > 0:
-                smp_mflags = '-j%d' % (cpus)
+                smp_mflags = '-j%d' % (cpus + 1)
         except:
             pass
     if uname[4].startswith('arm'):