diff --git a/.travis.yml b/.travis.yml
index e17a432..c0f0867 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -220,7 +220,8 @@ install:
 script:
   - |-
     echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
-  - ./b2 -j3 libs/integer/test toolset=$TOOLSET cxxstd=$CXXSTD
+  - BUILD_JOBS=`(nproc || sysctl -n hw.ncpu) 2> /dev/null`
+  - ./b2 -j $BUILD_JOBS libs/integer/test toolset=$TOOLSET cxxstd=$CXXSTD
 
 notifications:
   email:
diff --git a/appveyor.yml b/appveyor.yml
index 2cfaa3e..608f289 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -62,4 +62,4 @@ test_script:
   - ..\..\..\b2 config_info_travis_install %ARGS%
   - config_info_travis
   - cd ..\..\integer\test
-  - ..\..\..\b2 -j3 %ARGS% define=CI_SUPPRESS_KNOWN_ISSUES
+  - ..\..\..\b2 -j %NUMBER_OF_PROCESSORS% %ARGS% define=CI_SUPPRESS_KNOWN_ISSUES