diff --git a/docs/mods-and-plugins/modrinth.md b/docs/mods-and-plugins/modrinth.md
index 648f3e1e..d34acfbf 100644
--- a/docs/mods-and-plugins/modrinth.md
+++ b/docs/mods-and-plugins/modrinth.md
@@ -50,3 +50,5 @@
 `MODRINTH_ALLOWED_VERSION_TYPE`
 : The version type is used to determine the newest version to use from each project. The allowed values are `release` (default), `beta`, `alpha`. Setting to `beta` will pick up both release and beta versions. Setting to `alpha` will pick up release, beta, and alpha versions.
 
+`MODRINTH_LOADER`
+: When using a custom server, set this to specify which loader type will be requested during lookups
diff --git a/scripts/start-setupModpack b/scripts/start-setupModpack
index a9a982c3..fc29330b 100755
--- a/scripts/start-setupModpack
+++ b/scripts/start-setupModpack
@@ -12,6 +12,7 @@ set -e -o pipefail
 : "${REMOVE_OLD_MODS_DEPTH:=1} "
 : "${REMOVE_OLD_MODS_INCLUDE:=*.jar,*-version.json}"
 : "${CF_API_KEY_FILE:=}" # Path to file containing CurseForge API key
+: "${MODRINTH_LOADER:=}"
 sum_file=/data/.generic_pack.sum
 
 if [[ -n ${CF_API_KEY_FILE} ]]; then
@@ -263,13 +264,21 @@ function handleModrinthProjects() {
   fi
 
   if [[ $MODRINTH_PROJECTS ]]; then
-    if isFamily HYBRID; then
+
+    if isType CUSTOM; then
+      if ! [[ $MODRINTH_LOADER ]]; then
+        logError "MODRINTH_LOADER must be set when using TYPE=CUSTOM and MODRINTH_PROJECTS"
+        exit 1
+      fi
+      loader="${MODRINTH_LOADER,,}"
+    elif isFamily HYBRID; then
       loader=${HYBRIDTYPE}
     elif isFamily VANILLA; then
       loader=datapack
     else
       loader="${TYPE,,}"
     fi
+
     mc-image-helper modrinth \
       --output-directory=/data \
       --world-directory="${LEVEL:-world}" \
diff --git a/scripts/start-utils b/scripts/start-utils
index a3bc0bbc..00d13156 100755
--- a/scripts/start-utils
+++ b/scripts/start-utils
@@ -411,7 +411,7 @@ function isFamily() {
 function isType() {
   for t in "${@}"; do
     # shellcheck disable=SC2153
-    if [[ $TYPE == "$t" ]]; then
+    if [[ ${TYPE^^} == "${t^^}" ]]; then
       return 0
     fi
   done