diff --git a/build/deploy-phpdoc-branch.sh b/build/deploy-phpdoc-branch.sh
index 0d4335a..1b3e11e 100755
--- a/build/deploy-phpdoc-branch.sh
+++ b/build/deploy-phpdoc-branch.sh
@@ -15,19 +15,27 @@ if [ "$TRAVIS_SECURE_ENV_VARS" != "true" ]; then
     exit
 fi
 
-if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
-    echo "Skipping phpDoc deployment because this pull request (#$TRAVIS_PULL_REQUEST) is not permitted to deploy"
-    exit
-fi
-
 PHPDOC_ID="${TRAVIS_BRANCH//\//_}"
+PHPDOC_REF="heads/$TRAVIS_BRANCH"
+PHPDOC_REF_TEXT="$TRAVIS_BRANCH branch"
+
+if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
+    PHPDOC_ID="pull_$TRAVIS_PULL_REQUEST"
+    PHPDOC_REF="pull/$TRAVIS_PULL_REQUEST/head"
+    PHPDOC_REF_TEXT="pull request #$TRAVIS_PULL_REQUEST"
+
+    if [[ ",$DEPLOY_PHPDOC_BRANCHES," != *,"#$TRAVIS_PULL_REQUEST",* ]]; then
+        echo "Skipping phpDoc deployment because this pull request (#$TRAVIS_PULL_REQUEST) is not permitted to deploy"
+        exit
+    fi
+fi
 
 generate-phpdoc.sh \
     "$TRAVIS_BUILD_DIR" "$TRAVIS_BUILD_DIR/build/phpdoc-$PHPDOC_ID" \
-    "Pico 1.0 API Documentation ($TRAVIS_BRANCH branch)"
+    "Pico 1.0 API Documentation ($PHPDOC_REF_TEXT)"
 [ $? -eq 0 ] || exit 1
 
 deploy-phpdoc.sh \
-    "$TRAVIS_REPO_SLUG" "$TRAVIS_BRANCH @ $TRAVIS_COMMIT" "$TRAVIS_BUILD_DIR/build/phpdoc-$PHPDOC_ID" \
+    "$TRAVIS_REPO_SLUG" "$PHPDOC_REF @ $TRAVIS_COMMIT" "$TRAVIS_BUILD_DIR/build/phpdoc-$PHPDOC_ID" \
     "$TRAVIS_REPO_SLUG" "gh-pages" "phpDoc/$PHPDOC_ID"
 [ $? -eq 0 ] || exit 1
diff --git a/build/deploy-phpdoc-release.sh b/build/deploy-phpdoc-release.sh
index 6604ba6..f22030c 100755
--- a/build/deploy-phpdoc-release.sh
+++ b/build/deploy-phpdoc-release.sh
@@ -3,13 +3,15 @@
 [ "$DEPLOY_PHPDOC_RELEASES" == "true" ] || exit
 
 PHPDOC_ID="${TRAVIS_BRANCH//\//_}"
+PHPDOC_REF="tags/$TRAVIS_TAG"
+PHPDOC_REF_TEXT="$TRAVIS_TAG"
 
 generate-phpdoc.sh \
     "$TRAVIS_BUILD_DIR" "$TRAVIS_BUILD_DIR/build/phpdoc-$PHPDOC_ID" \
-    "Pico 1.0 API Documentation ($TRAVIS_TAG)"
+    "Pico 1.0 API Documentation ($PHPDOC_REF_TEXT)"
 [ $? -eq 0 ] || exit 1
 
 deploy-phpdoc.sh \
-    "$TRAVIS_REPO_SLUG" "$TRAVIS_TAG" "$TRAVIS_BUILD_DIR/build/phpdoc-$PHPDOC_ID" \
+    "$TRAVIS_REPO_SLUG" "$PHPDOC_REF" "$TRAVIS_BUILD_DIR/build/phpdoc-$PHPDOC_ID" \
     "$TRAVIS_REPO_SLUG" "gh-pages" "phpDoc/$PHPDOC_ID"
 [ $? -eq 0 ] || exit 1
diff --git a/build/deploy-phpdoc.sh b/build/deploy-phpdoc.sh
index 57b5c6b..26d06b8 100755
--- a/build/deploy-phpdoc.sh
+++ b/build/deploy-phpdoc.sh
@@ -10,7 +10,8 @@ BASE_PWD="$PWD"
 
 # parameters
 SOURCE_REPO_SLUG="$1"       # source GitHub repo (e.g. picocms/Pico)
-SOURCE_REF="$2"             # source reference (either [branch]@[commit], [branch] or [tag])
+SOURCE_REF="$2"             # source reference (either "[ref] @ [commit]" or "[ref]",
+                            #                   [ref] can be e.g. heads/master or tags/v1.0.0)
 SOURCE_DIR="$3"             # absolute source path
 TARGET_REPO_SLUG="$4"       # target GitHub repo (e.g. picocms/Pico)
 TARGET_BRANCH="$5"          # target branch (e.g. gh-pages)
@@ -26,24 +27,20 @@ printf 'TARGET_BRANCH="%s"\n' "$TARGET_BRANCH"
 printf 'TARGET_DIR="%s"\n' "$TARGET_DIR"
 echo
 
-# evaluate target reference
-if git check-ref-format "tags/$SOURCE_REF"; then
-    SOURCE_REF_TYPE="tag"
-    SOURCE_REF_TAG="$SOURCE_REF"
-elif [[ "$SOURCE_REF" == *" @ "* ]]; then
+# evaluate source reference
+if [[ "$SOURCE_REF" == *" @ "* ]]; then
     SOURCE_REF_TYPE="commit"
-    SOURCE_REF_BRANCH="${SOURCE_REF% @ *}"
+    SOURCE_REF_HEAD="${SOURCE_REF% @ *}"
     SOURCE_REF_COMMIT="${SOURCE_REF##* @ }"
 
-    if ! git check-ref-format "heads/$SOURCE_REF_BRANCH" || ! git rev-parse --verify "$SOURCE_REF_COMMIT" > /dev/null; then
-        echo "FATAL: $APP_NAME target reference '$SOURCE_REF' is invalid" >&2
+    if ! git check-ref-format "$SOURCE_REF_HEAD" || ! git rev-parse --verify "$SOURCE_REF_COMMIT" > /dev/null; then
+        echo "FATAL: $APP_NAME source reference '$SOURCE_REF' is invalid" >&2
         exit 1
     fi
-elif git check-ref-format "heads/$SOURCE_REF"; then
-    SOURCE_REF_TYPE="branch"
-    SOURCE_REF_BRANCH="$SOURCE_REF"
+elif git check-ref-format "$SOURCE_REF"; then
+    SOURCE_REF_TYPE="ref"
 else
-    echo "FATAL: $APP_NAME target reference '$SOURCE_REF' is invalid" >&2
+    echo "FATAL: $APP_NAME source reference '$SOURCE_REF' is invalid" >&2
     exit 1
 fi
 
@@ -79,7 +76,7 @@ git commit --message="Update phpDocumentor class docs for $SOURCE_REF"
 if [ "$SOURCE_REF_TYPE" == "commit" ]; then
     # load branch data via GitHub APIv3
     printf '\nRetrieving latest commit...\n'
-    LATEST_COMMIT_URL="https://api.github.com/repos/$SOURCE_REPO_SLUG/git/refs/heads/$SOURCE_REF_BRANCH"
+    LATEST_COMMIT_URL="https://api.github.com/repos/$SOURCE_REPO_SLUG/git/refs/$SOURCE_REF_HEAD"
     if [ -n "$GITHUB_OAUTH_TOKEN" ]; then
         LATEST_COMMIT_RESPONSE="$(wget -O- --header="Authorization: token $GITHUB_OAUTH_TOKEN" "$LATEST_COMMIT_URL" 2> /dev/null)"
     else
@@ -90,7 +87,7 @@ if [ "$SOURCE_REF_TYPE" == "commit" ]; then
     LATEST_COMMIT="$(echo "$LATEST_COMMIT_RESPONSE" | php -r "
         \$json = json_decode(stream_get_contents(STDIN), true);
         if (\$json !== null) {
-            if (isset(\$json['ref']) && (\$json['ref'] === 'refs/heads/$SOURCE_REF_BRANCH')) {
+            if (isset(\$json['ref']) && (\$json['ref'] === 'refs/$SOURCE_REF_HEAD')) {
                 if (isset(\$json['object']) && isset(\$json['object']['sha'])) {
                     echo \$json['object']['sha'];
                 }
@@ -98,7 +95,7 @@ if [ "$SOURCE_REF_TYPE" == "commit" ]; then
         }
     ")"
 
-    # compare target reference against the latest commit
+    # compare source reference against the latest commit
     if [ "$LATEST_COMMIT" != "$SOURCE_REF_COMMIT" ]; then
         echo "WARNING: $APP_NAME source reference '$SOURCE_REF' doesn't match the latest commit '$LATEST_COMMIT'" >&2
         exit 0