diff --git a/scripts/update_dependencies.sh b/scripts/update_dependencies.sh
index 037c064d9..bbb95e766 100755
--- a/scripts/update_dependencies.sh
+++ b/scripts/update_dependencies.sh
@@ -9,21 +9,21 @@ set -o nounset
 # structure will be lost.
 # http://git.661346.n2.nabble.com/subtree-merges-lose-prefix-after-rebase-td7332850.html
 
-OSMIUM_REPO=https://github.com/osmcode/libosmium.git
+OSMIUM_REPO="https://github.com/osmcode/libosmium.git"
 OSMIUM_TAG=v2.10.2
 
-VARIANT_REPO=https://github.com/mapbox/variant.git
+VARIANT_REPO="https://github.com/mapbox/variant.git"
 VARIANT_TAG=v1.1.0
 
-MASON_REPO=https://github.com/mapbox/mason.git
+MASON_REPO="https://github.com/mapbox/mason.git"
 MASON_TAG=v0.3.0
 
 SOL_REPO="https://github.com/ThePhD/sol2.git"
 SOL_TAG=v2.15.4
 
-VARIANT_LATEST=$(curl https://api.github.com/repos/mapbox/variant/releases/latest | jq ".tag_name")
-OSMIUM_LATEST=$(curl https://api.github.com/repos/osmcode/libosmium/releases/latest | jq ".tag_name")
-MASON_LATEST=$(curl https://api.github.com/repos/mapbox/mason/releases/latest | jq ".tag_name")
+VARIANT_LATEST=$(curl "https://api.github.com/repos/mapbox/variant/releases/latest" | jq ".tag_name")
+OSMIUM_LATEST=$(curl "https://api.github.com/repos/osmcode/libosmium/releases/latest" | jq ".tag_name")
+MASON_LATEST=$(curl "https://api.github.com/repos/mapbox/mason/releases/latest" | jq ".tag_name")
 SOL_LATEST=$(curl "https://api.github.com/repos/ThePhD/sol2/releases/latest" | jq ".tag_name")
 
 echo "Latest osmium release is $OSMIUM_LATEST, pulling in \"$OSMIUM_TAG\""
@@ -31,12 +31,44 @@ echo "Latest variant release is $VARIANT_LATEST, pulling in \"$VARIANT_TAG\""
 echo "Latest mason release is $MASON_LATEST, pulling in \"$MASON_TAG\""
 echo "Latest sol2 release is $SOL_LATEST, pulling in \"$SOL_TAG\""
 
-read -p "Looks good? (Y/n) " ok
-
+read -p "Update osmium (y/n) " ok
 if [[ $ok =~ [yY] ]]
 then
-  git subtree pull -P third_party/libosmium/ $OSMIUM_REPO $OSMIUM_TAG --squash
-  git subtree pull -P third_party/variant/ $VARIANT_REPO $VARIANT_TAG --squash
-  git subtree pull -P third_party/mason/ $MASON_REPO $MASON_TAG --squash
-  git subtree pull -P third_party/sol2/sol2/ $SOL_REPO $SOL_TAG --squash
+  if [ -d "third_party/libosmium" ]; then
+    git subtree pull -P third_party/libosmium/ $OSMIUM_REPO $OSMIUM_TAG --squash
+  else
+    git subtree add -P third_party/libosmium/ $OSMIUM_REPO $OSMIUM_TAG --squash
+  fi
 fi
+
+read -p "Update variant (y/n) " ok
+if [[ $ok =~ [yY] ]]
+then
+  if [ -d "third_party/variant" ]; then
+    git subtree pull -P third_party/variant/ $VARIANT_REPO $VARIANT_TAG --squash
+  else
+    git subtree add -P third_party/variant/ $VARIANT_REPO $VARIANT_TAG --squash
+  fi
+fi
+
+read -p "Update mason (y/n) " ok
+if [[ $ok =~ [yY] ]]
+then
+  if [ -d "third_party/mason" ]; then
+    git subtree pull -P third_party/mason/ $MASON_REPO $MASON_TAG --squash
+  else
+    git subtree add -P third_party/mason/ $MASON_REPO $MASON_TAG --squash
+  fi
+fi
+
+read -p "Update sol2 (y/n) " ok
+if [[ $ok =~ [yY] ]]
+then
+  if [ -d "third_party/sol2" ]; then
+    git subtree pull -P third_party/sol2/sol2/ $SOL_REPO $SOL_TAG --squash
+  else
+    git subtree add -P third_party/sol2/sol2/ $SOL_REPO $SOL_TAG --squash
+  fi
+fi
+
+