diff --git a/dist/tools/git/README.md b/dist/tools/git/README.md
index 430b5d890b2a42a87c165d976d4e6cd406fdfa60..e55b492de7e8ac261a130db9fb7483f08a8b3756 100644
--- a/dist/tools/git/README.md
+++ b/dist/tools/git/README.md
@@ -16,6 +16,10 @@ In order to set up the cache, do:
   The used path can be overridden using the "GIT_CACHE_DIR" environment
   variable.
   The cache repository will be used to cache multiple remote repositories.
-- add a repository to the cache: "git cache add \<name\> \<URL\>
+- add a repository to the cache: "git cache add \<URL\> [\<name\>]
 - whenever needed (at least once after adding a repository),
   run "git cache update"
+
+If the GIT_CACHE_AUTOADD environment variable is set to "1", a "git cache
+clone" will add the repository to the cache (and immediately update) if the url
+is not yet in the cache.
diff --git a/dist/tools/git/git-cache b/dist/tools/git/git-cache
index b666409dbe2ebb7ffec979e85c685000a2789375..f19ccd9441836da2886b331c26ef3744ad94c37d 100755
--- a/dist/tools/git/git-cache
+++ b/dist/tools/git/git-cache
@@ -6,7 +6,8 @@ git_cache() {
 
 init() {
     set -ex
-    test -d "${GIT_CACHE_DIR}/.git" || {
+    local _git_dir="$(git_cache rev-parse --git-dir 2>/dev/null)"
+    test "$_git_dir" == "." -o "$_git_dir" == ".git" || {
         mkdir -p "${GIT_CACHE_DIR}"
 
         git_cache init --bare
@@ -17,7 +18,19 @@ init() {
 
 add() {
     set -ex
-    git_cache remote add $1 $2
+    if [ $# -eq 1 ]; then
+        local repo="$1"
+        local name="$(_remote_name $repo)"
+    else
+        local repo="$1"
+        local name="$2"
+    fi
+
+    if ! is_cached "$repo"; then
+        git_cache remote add "$name" "$repo"
+    else
+        echo "git-cache: $url already in cache"
+    fi
     set +ex
 }
 
@@ -28,6 +41,17 @@ update() {
     set +ex
 }
 
+is_cached() {
+    set +ex
+    local url="$1"
+    local REMOTES="$(git_cache remote show)"
+    for remote in $REMOTES; do
+        test "$(git_cache remote get-url $remote)" == "$url" && return 0
+    done
+    set -ex
+    return 1
+}
+
 list() {
     local REMOTES="$(git_cache remote show)"
     for remote in $REMOTES; do
@@ -50,13 +74,24 @@ _check_commit() {
     git_cache cat-file -e ${1}^{commit}
 }
 
+_remote_name() {
+    basename "$*" .git
+}
+
 clone() {
     set -ex
     local REMOTE="${1}"
     local SHA1="${2}"
-    local REMOTE_NAME="$(basename $REMOTE)"
+    local REMOTE_NAME="$(_remote_name $REMOTE)"
     local TARGET_PATH="${3:-${REMOTE_NAME}}"
 
+    if [ "$GIT_CACHE_AUTOADD" == "1" ]; then
+        if ! is_cached "$REMOTE"; then
+            add "$REMOTE"
+            update "$(_remote_name $REMOTE)"
+        fi
+    fi
+
     if _check_commit $2 2>&1; then
         git init "${TARGET_PATH}"
         git_cache tag commit$SHA1 $SHA1 || true # ignore possibly already existing tag
@@ -76,7 +111,8 @@ usage() {
     echo "usage:"
     echo ""
     echo "    git cache init                initialize git cache"
-    echo "    git cache add <name> <url>    add repository <url> with name <name>"
+    echo "    git cache add <url> [<name>]  add repository <url> with name <name>"
+    echo "                                  (if no name given, use \"basename $url .git\""
     echo "    git cache list                list cached repositories"
     echo "    git cache drop <name>         drop repo from cache"
     echo "    git cache update [<name>]     fetch repo named <name> (or all)"