diff --git a/.travis.yml b/.travis.yml
index 390caf8..83207ae 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -339,7 +339,7 @@ install:
 script:
   - |-
     echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
-  - ./b2 libs/preprocessor/test -j 3 toolset=$TOOLSET cxxstd=$CXXSTD $ADDRMD
+  - ./b2 libs/preprocessor/test -j $nproc toolset=$TOOLSET cxxstd=$CXXSTD $ADDRMD
 
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