diff --git a/opensaas-sh/README.md b/opensaas-sh/README.md
index fcee7ce..1e916a9 100644
--- a/opensaas-sh/README.md
+++ b/opensaas-sh/README.md
@@ -26,18 +26,6 @@ If you're running the `patch.sh` or `diff.sh` scripts on Mac, you need to instal
 - `gpatch`,
 - and `diffutils`.
 
-You should also create aliases for `realpath` and `patch`:
-
-```sh
-brew install coreutils # contains grealpath
-brew install gpatch
-brew install diffutils
-
-echo 'alias realpath="grealpath"' >> ~/.zshrc
-echo 'alias patch="gpatch"' >> ~/.zshrc
-source ~/.zshrc
-```
-
 Make sure not to commit `app/` to git. It is currently (until we resolve this) not added to .gitignore because that messes up diffing for us.
 
 ### Blog (blog/)
diff --git a/opensaas-sh/tools/dope.sh b/opensaas-sh/tools/dope.sh
index 34222fe..b52d5af 100755
--- a/opensaas-sh/tools/dope.sh
+++ b/opensaas-sh/tools/dope.sh
@@ -5,6 +5,19 @@
 # Allows you to easily create a diff between the two projects (base and derived), or to patch those diffs onto the base project to get the derived one.
 # Useful when derived project has only small changes on top of base project and you want to keep it in a dir in the same repo as main project.
 
+# Determine the patch command to use based on OS
+PATCH_CMD="patch"
+if [[ "$(uname)" == "Darwin" ]]; then
+    # On macOS, require gpatch to be installed
+    if command -v gpatch &> /dev/null; then
+        PATCH_CMD="gpatch"
+    else
+        echo "Error: GNU patch (gpatch) not found. On MacOS, this script requires GNU patch."
+        echo "Install it with: brew install gpatch"
+        exit 1
+    fi
+fi
+
 # List all the source files in the specified dir.
 # "Source" files are any files that are not gitignored.
 list_source_files() {
@@ -92,7 +105,7 @@ recreate_derived_dir() {
 
         local patch_output
         local patch_exit_code
-        patch_output=$(patch --no-backup-if-mismatch --merge "${DERIVED_DIR}/${derived_filepath}" < "${diff_filepath}")
+        patch_output=$("${PATCH_CMD}" --no-backup-if-mismatch --merge "${DERIVED_DIR}/${derived_filepath}" < "${diff_filepath}")
         patch_exit_code=$?
         if [ ${patch_exit_code} -eq 0 ]; then
           echo "${patch_output}"