diff --git a/.travis.yml b/.travis.yml
index eae103bf..59d56a32 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,91 +9,91 @@ env:
 
 matrix:
   include:
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py37" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
-#      sudo: required
-#      services:
-#      - docker
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py36" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
-#      sudo: required
-#      services:
-#      - docker
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py27" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
-#      sudo: required
-#      services:
-#      - docker
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py27mu" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
-#      sudo: required
-#      services:
-#      - docker
-#   - env: PAGMO_PLUGINS_NONFREE_BUILD="DebugGCC"
-#     dist: bionic
-#     compiler: gcc
-#     os: linux
-#     addons:
-#       apt:
-#         sources:
-#         - ubuntu-toolchain-r-test
-#         packages:
-#         - binutils-gold
-#   - env: PAGMO_PLUGINS_NONFREE_BUILD="ReleaseGCC"
-#     dist: bionic
-#     compiler: gcc
-#     os: linux
-#     addons:
-#       apt:
-#         sources:
-#         - ubuntu-toolchain-r-test
-#         packages:
-#         - binutils-gold
-#   - env: PAGMO_PLUGINS_NONFREE_BUILD="CoverageGCC"
-#     dist: bionic
-#     compiler: gcc
-#     os: linux
-#     addons:
-#       apt:
-#         sources:
-#         - ubuntu-toolchain-r-test
-#         packages:
-#         - binutils-gold
-#   - env: PAGMO_PLUGINS_NONFREE_BUILD="ReleaseClang"
-#     dist: bionic
-#     compiler: clang
-#     os: linux
-#     addons:
-#       apt:
-#         sources:
-#         - ubuntu-toolchain-r-test
-#         packages:
-#         - clang-7
-#   - env: PAGMO_PLUGINS_NONFREE_BUILD="DebugClang"
-#     dist: bionic
-#     compiler: clang
-#     os: linux
-#     addons:
-#       apt:
-#         sources:
-#         - ubuntu-toolchain-r-test
-#         packages:
-#         - clang-7
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="Python37"
-#    - dist: bionic
-#      compiler: gcc
-#      os: linux
-#      addons:
-#        apt:
-#          sources:
-#          - ubuntu-toolchain-r-test
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="Python27"
-#      compiler: gcc
-#      os: linux
-#      addons:
-#        apt:
-#          sources:
-#          - ubuntu-toolchain-r-test
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="OSXDebug"
-#      os: osx
-#    - env: PAGMO_PLUGINS_NONFREE_BUILD="OSXRelease"
-#      os: osx
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py37" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
+      sudo: required
+      services:
+      - docker
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py36" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
+      sudo: required
+      services:
+      - docker
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py27" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
+      sudo: required
+      services:
+      - docker
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="manylinux64Py27mu" DOCKER_IMAGE="pagmo2/manylinux1_x86_64_with_deps"
+      sudo: required
+      services:
+      - docker
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="DebugGCC"
+      dist: bionic
+      compiler: gcc
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+          packages:
+          - binutils-gold
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="ReleaseGCC"
+      dist: bionic
+      compiler: gcc
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+          packages:
+          - binutils-gold
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="CoverageGCC"
+      dist: bionic
+      compiler: gcc
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+          packages:
+          - binutils-gold
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="ReleaseClang"
+      dist: bionic
+      compiler: clang
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+          packages:
+          - clang-7
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="DebugClang"
+      dist: bionic
+      compiler: clang
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+          packages:
+          - clang-7
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="Python37"
+    - dist: bionic
+      compiler: gcc
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="Python27"
+      compiler: gcc
+      os: linux
+      addons:
+        apt:
+          sources:
+          - ubuntu-toolchain-r-test
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="OSXDebug"
+      os: osx
+    - env: PAGMO_PLUGINS_NONFREE_BUILD="OSXRelease"
+      os: osx
     - env: PAGMO_PLUGINS_NONFREE_BUILD="OSXPython37"
       os: osx
       osx_image: xcode6.4