diff --git a/.travis.yml b/.travis.yml
index 1e419e6e..2e8e156e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -55,7 +55,7 @@ install:
      echo "cabal build-cache MISS";
      rm -rf $HOME/.cabsnap;
      mkdir -p $HOME/.ghc $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin;
-     cabal install -j --only-dependencies --enable-tests --enable-benchmarks;
+     cabal install -j1 --only-dependencies --enable-tests --enable-benchmarks;
    fi
 
 # snapshot package-db on cache miss
@@ -72,8 +72,8 @@ install:
 script:
  - if [ -f configure.ac ]; then autoreconf -i; fi
  - cabal configure --enable-tests -v2  # -v2 provides useful information for debugging
- - cabal build -j # this builds all libraries and executables (including tests/benchmarks)
- - cabal test -j --show-details=always
+ - cabal build -j1 # this builds all libraries and executables (including tests/benchmarks)
+ - cabal test -j1 --show-details=always
  - cabal check
  - cabal sdist   # tests that a source-distribution can be generated