diff --git a/package/linux/travis-build-main.sh b/package/linux/travis-build-main.sh
index 037c1d1bf..dce24f540 100755
--- a/package/linux/travis-build-main.sh
+++ b/package/linux/travis-build-main.sh
@@ -3,25 +3,23 @@
 # This is too strict for source $HOME/perl5/perlbrew/etc/bashrc:
 ### set -euo pipefail
 
-if [ ! -d $HOME/perl5/perlbrew/perls ]; then
+if [ ! -d $HOME/perl5/perlbrew/perls/slic3r-perl ]; then
     echo "Downloading slic3r-perl.524.travis.tar.bz2"
     curl -L "http://www.siusgs.com/slic3r/buildserver/slic3r-perl.524.gcc49.travis.tar.bz2" -o /tmp/slic3r-perlbrew-5.24.tar.bz2; 
     tar -C$HOME/perl5/perlbrew/perls -xjf $CACHE/slic3r-perlbrew-5.24.tar.bz2
 fi
 
-if [ ! -d $HOME/boost_1_63_0 ]; then
+if [ ! -e $HOME/boost_1_63_0/boost/version.hpp ]; then
     echo "Downloading boost_1_63_0.built.gcc-4.9.4-buildserver.tar.bz2"
     curl -L "http://www.siusgs.com/slic3r/buildserver/boost_1_63_0.built.gcc-4.9.4-buildserver.tar.bz2" -o /tmp/boost-compiled.tar.bz2
     tar -C$HOME -xjf /tmp/boost-compiled.tar.bz2
 fi
 
-if [ ! -d $TRAVIS_BUILD_DIR/local-lib ]; then
+if !(perl -MWx -e1 2> /dev/null); then
     echo "Downloading slic3r-dependencies.gcc49.travis-wx302.tar.bz2"
     curl -L "http://www.siusgs.com/slic3r/buildserver/slic3r-dependencies.travis-wx302.tar.bz2" -o /tmp/local-lib-wx302.tar.bz2
     tar -C$TRAVIS_BUILD_DIR -xjf /tmp/local-lib-wx302.tar.bz2
-fi
-
-if [ ! -d $HOME/wx302 ]; then
+    
     echo "Downloading buildserver/wx302-libs.tar.bz2"
     curl -L "http://www.siusgs.com/slic3r/buildserver/wx302-libs.tar.bz2" -o /tmp/wx302.tar.bz2
     tar -C$HOME -xjf /tmp/wx302.tar.bz2
diff --git a/package/osx/travis-build-main.sh b/package/osx/travis-build-main.sh
index 62b5bb8d2..aa29c712d 100755
--- a/package/osx/travis-build-main.sh
+++ b/package/osx/travis-build-main.sh
@@ -9,7 +9,7 @@ export BOOST_DIR=/usr/local
 perl ./Build.PL
 
 # Only recompile Wx if it's not already there
-if !(perl -MWx -e1 2> /dev/null); then
+if !(perl -MWx -e1); then
     # our patch-wxwidgets.diff assumes Alien::wxWidgets installs wxWidgets 3.0.2
     PERL_USE_UNSAFE_INC=1 \
         CXX="clang++ -mmacosx-version-min=10.12" \