diff --git a/.travis.yml b/.travis.yml
index 56d4a600b..2d7b69f6d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,10 +36,8 @@ branches:
 
 # Additional installs: Valgrind for memory tests.
 install:
-  - sudo apt-get update -qq
-  - sudo apt-get install valgrind
-  - apt-cache search gcc | grep '^gcc-[0-9\.]* '
-  - apt-cache search clang | grep compiler
+  - '[ "$OS" != "WIN" ] && sudo apt-get update -qq || true'
+  - '[ "$OS" != "WIN" ] && sudo apt-get install valgrind || true'
 
 # The language is C and it will load the respective dependencies
 language: c
@@ -60,96 +58,113 @@ matrix:
     # We have only one program and the variable $BUILDOPTIONS
     # has only the options to that program: testme.sh
 
-    # Check source code format
-    - env: BUILDOPTIONS='--format'
-      addons:
-        apt:
-          packages:
-            - astyle
-
-    # GCC for the 32-bit architecture (no valgrind yet)
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --with-m32'
-      addons:
-        apt:
-          packages:
-            - libc6-dev-i386
-            - gcc-multilib
-
-    # clang for the 32-bit architecture (no valgrind yet)
-    - env: BUILDOPTIONS='--with-cc=clang-7 --with-m32'
-      addons:
-        apt:
-          packages:
-            - libc6-dev-i386
-            - gcc-multilib
-
-    # GCC for the x64_32 architecture (32-bit longs and 32-bit pointers)
-    # TODO: Probably not possible to run anything in x32 in Travis
-    #       but needs to be checked to be sure.
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --with-mx32'
-      addons:
-        apt:
-          packages:
-            - libc6-dev-x32
-            - gcc-multilib
-
-    # GCC for the x86-64 architecture (64-bit longs and 64-bit pointers)
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --with-m64 --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=gcc-4.7 --with-m64 --with-valgrind'
-      addons:
-        apt:
-          packages:
-            - gcc-4.7
-    - env: BUILDOPTIONS='--with-cc=gcc-4.8 --with-m64 --with-valgrind'
-      addons:
-        apt:
-          packages:
-            - gcc-4.8
-    - env: BUILDOPTIONS='--with-cc=gcc-4.9 --with-m64 --with-valgrind'
-      addons:
-        apt:
-          packages:
-            - gcc-4.9
-
-    # clang for x86-64 architecture (64-bit longs and 64-bit pointers)
-    - env: CONV_WARNINGS=1 BUILDOPTIONS='--with-cc=clang-7 --with-m64 --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=clang-6.0 --with-m64 --with-valgrind'
-      addons:
-        apt:
-          packages:
-            - clang-6.0
-    - env: BUILDOPTIONS='--with-cc=clang-5.0 --with-m64 --with-valgrind'
-      addons:
-        apt:
-          packages:
-            - clang-5.0
-    - env: BUILDOPTIONS='--with-cc=clang-4.0 --with-m64 --with-valgrind'
-      addons:
-        apt:
-          packages:
-            - clang-4.0
-
-    # GCC for the x86-64 architecture with restricted limb sizes
-    # formerly started with the option "--with-low-mp" to testme.sh
-    # but testing all three in one run took to long and timed out.
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --cflags=-DMP_8BIT  --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --cflags=-DMP_16BIT --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --cflags=-DMP_32BIT --with-valgrind'
-
-    # clang for the x86-64 architecture with restricted limb sizes
-    - env: BUILDOPTIONS='--with-cc=clang-7 --cflags=-DMP_8BIT  --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=clang-7 --cflags=-DMP_16BIT --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=clang-7 --cflags=-DMP_32BIT --with-valgrind'
-
-    # GCC for the x86-64 architecture testing against a different Bigint-implementation
-    # with 333333 different inputs.
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --test-vs-mtest=333333 --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=clang-7 --test-vs-mtest=333333 --with-valgrind'
-
-    # clang for the x86-64 architecture testing against a different Bigint-implementation
-    # with a better random source.
-    - env: BUILDOPTIONS='--with-cc=gcc-5 --test-vs-mtest=333333 --mtest-real-rand --with-valgrind'
-    - env: BUILDOPTIONS='--with-cc=clang-7 --test-vs-mtest=333333 --mtest-real-rand --with-valgrind'
+#    # Check source code format
+#    - env: BUILDOPTIONS='--format'
+#      addons:
+#        apt:
+#          packages:
+#            - astyle
+
+    # Windows build with gcc
+    - os: windows
+      env: 
+      - OS=WIN
+      - BUILDOPTIONS='--all'
+      before_script:
+        - chmod +x testme.sh
+
+    # Windows build with msvc
+    - os: windows
+      env:
+      - OS=WIN
+      - BUILDOPTIONS='--make=nmake.exe --make-options=-f --make-options=makefile.msvc'
+      before_script:
+        - . '"C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Auxiliary\Build\vcvarsall.bat" amd64'
+        - chmod +x testme.sh
+
+#    # GCC for the 32-bit architecture (no valgrind yet)
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --with-m32'
+#      addons:
+#        apt:
+#          packages:
+#            - libc6-dev-i386
+#            - gcc-multilib
+#
+#    # clang for the 32-bit architecture (no valgrind yet)
+#    - env: BUILDOPTIONS='--with-cc=clang-7 --with-m32'
+#      addons:
+#        apt:
+#          packages:
+#            - libc6-dev-i386
+#            - gcc-multilib
+#
+#    # GCC for the x64_32 architecture (32-bit longs and 32-bit pointers)
+#    # TODO: Probably not possible to run anything in x32 in Travis
+#    #       but needs to be checked to be sure.
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --with-mx32'
+#      addons:
+#        apt:
+#          packages:
+#            - libc6-dev-x32
+#            - gcc-multilib
+#
+#    # GCC for the x86-64 architecture (64-bit longs and 64-bit pointers)
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --with-m64 --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=gcc-4.7 --with-m64 --with-valgrind'
+#      addons:
+#        apt:
+#          packages:
+#            - gcc-4.7
+#    - env: BUILDOPTIONS='--with-cc=gcc-4.8 --with-m64 --with-valgrind'
+#      addons:
+#        apt:
+#          packages:
+#            - gcc-4.8
+#    - env: BUILDOPTIONS='--with-cc=gcc-4.9 --with-m64 --with-valgrind'
+#      addons:
+#        apt:
+#          packages:
+#            - gcc-4.9
+#
+#    # clang for x86-64 architecture (64-bit longs and 64-bit pointers)
+#    - env: CONV_WARNINGS=1 BUILDOPTIONS='--with-cc=clang-7 --with-m64 --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=clang-6.0 --with-m64 --with-valgrind'
+#      addons:
+#        apt:
+#          packages:
+#            - clang-6.0
+#    - env: BUILDOPTIONS='--with-cc=clang-5.0 --with-m64 --with-valgrind'
+#      addons:
+#        apt:
+#          packages:
+#            - clang-5.0
+#    - env: BUILDOPTIONS='--with-cc=clang-4.0 --with-m64 --with-valgrind'
+#      addons:
+#        apt:
+#          packages:
+#            - clang-4.0
+#
+#    # GCC for the x86-64 architecture with restricted limb sizes
+#    # formerly started with the option "--with-low-mp" to testme.sh
+#    # but testing all three in one run took to long and timed out.
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --cflags=-DMP_8BIT  --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --cflags=-DMP_16BIT --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --cflags=-DMP_32BIT --with-valgrind'
+#
+#    # clang for the x86-64 architecture with restricted limb sizes
+#    - env: BUILDOPTIONS='--with-cc=clang-7 --cflags=-DMP_8BIT  --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=clang-7 --cflags=-DMP_16BIT --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=clang-7 --cflags=-DMP_32BIT --with-valgrind'
+#
+#    # GCC for the x86-64 architecture testing against a different Bigint-implementation
+#    # with 333333 different inputs.
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --test-vs-mtest=333333 --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=clang-7 --test-vs-mtest=333333 --with-valgrind'
+#
+#    # clang for the x86-64 architecture testing against a different Bigint-implementation
+#    # with a better random source.
+#    - env: BUILDOPTIONS='--with-cc=gcc-5 --test-vs-mtest=333333 --mtest-real-rand --with-valgrind'
+#    - env: BUILDOPTIONS='--with-cc=clang-7 --test-vs-mtest=333333 --mtest-real-rand --with-valgrind'
 
 # Notifications go to
 # An email address is also possible.
@@ -157,9 +172,5 @@ notifications:
   irc: "chat.freenode.net#libtom-notifications"
 
 # The actual script the jobs run.
-# Because of a default timeout of 10 minutes it was necessary to use
-# a Travis tool to extend that timeout to 40 minutes. 50 minutes
-# seem to be the max and 20 the default if travis_wait is called without
-# any options.
 script:
   - ./testme.sh ${BUILDOPTIONS}
diff --git a/testme.sh b/testme.sh
index 40ecb74f7..9239103e1 100755
--- a/testme.sh
+++ b/testme.sh
@@ -8,11 +8,16 @@
 
 set -e
 
+[ ! -z "$MAKE" ] || MAKE=make
+
 if [ -f /proc/cpuinfo ]
 then
-  MAKE_JOBS=$(( ($(cat /proc/cpuinfo | grep -E '^processor[[:space:]]*:' | tail -n -1 | cut -d':' -f2) + 1) * 2 + 1 ))
+  MAKE_JOBS="-j$(( ($(cat /proc/cpuinfo | grep -E '^processor[[:space:]]*:' | tail -n -1 | cut -d':' -f2) + 1) * 2 + 1 ))"
+elif [ "$MAKE" == "make" ]
+then
+  MAKE_JOBS="-j8"
 else
-  MAKE_JOBS=8
+  MAKE_JOBS=""
 fi
 
 ret=0
@@ -49,7 +54,11 @@ _help()
   echo "                            This is an option that will always be"
   echo "                            passed as parameter to CC."
   echo
-  echo "    --make-option=*         Give an option to make,"
+  echo "    --make=*                Use the given command instead of \""$MAKE"\"."
+  echo "                            This can also be accomplished by setting"
+  echo "                            the MAKE environment variable."
+  echo
+  echo "    --make-options=*        Give an option to make,"
   echo "                            e.g. --make-option=\"-f makefile.shared\""
   echo "                            This is an option that will always be"
   echo "                            passed as parameter to make."
@@ -105,7 +114,7 @@ _make()
 {
   echo -ne " Compile $1 $2"
   suffix=$(echo ${1}${2}  | tr ' ' '_')
-  CC="$1" CFLAGS="$2 $TEST_CFLAGS" make -j$MAKE_JOBS $3 $MAKE_OPTIONS > /dev/null 2>gcc_errors_${suffix}.log
+  CC="$1" CFLAGS="$2 $TEST_CFLAGS" $MAKE $MAKE_JOBS $3 $MAKE_OPTIONS > /dev/null 2>gcc_errors_${suffix}.log
   errcnt=$(wc -l < gcc_errors_${suffix}.log)
   if [[ ${errcnt} -gt 1 ]]; then
     echo " failed"
@@ -117,7 +126,7 @@ _make()
 
 _runtest()
 {
-  make clean > /dev/null
+  $MAKE clean > /dev/null
   _make "$1" "$2" "test_standalone"
   local _timeout=""
   which timeout >/dev/null && _timeout="timeout --foreground 90"
@@ -130,7 +139,7 @@ _runtest()
 # TODO: merge
 _runvalgrind()
 {
-  make clean > /dev/null
+  $MAKE clean > /dev/null
   _make "$1" "$2" "test_standalone"
   local _timeout=""
   # 30 minutes? Yes. Had it at 20 minutes and the Valgrind run needed over 25 minutes.
@@ -212,7 +221,10 @@ do
       fi
       start_alive_printing
     ;;
-    --make-option=*)
+    --make=*)
+      MAKE="${1#*=}"
+    ;;
+    --make-options=*)
       MAKE_OPTIONS="$MAKE_OPTIONS ${1#*=}"
     ;;
     --with-low-mp)
@@ -258,9 +270,9 @@ function _check_git() {
 
 if [[ "$CHECK_FORMAT" == "1" ]]
 then
-  make astyle
+  $MAKE astyle
   _check_git "make astyle"
-  make new_file
+  $MAKE new_file
   _check_git "make format"
   perl helper.pl -a
   exit $?
@@ -299,7 +311,7 @@ _banner
 
 if [[ "$TEST_VS_MTEST" != "" ]]
 then
-   make clean > /dev/null
+   $MAKE clean > /dev/null
    _make "${compilers[0]} ${archflags[0]}" "$CFLAGS" "test"
    echo
    _make "gcc" "$MTEST_RAND" "mtest"