diff --git a/INSTALL.md b/INSTALL.md
index f2345bc8..26fb9030 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -62,6 +62,9 @@ Dendrite requires a postgres database engine, version 9.5 or later.
   ```bash
   sudo -u postgres createuser -P dendrite     # prompts for password
   ```
+
+On macOS, omit `sudo -u postgres`.
+
 * Create databases:
   ```bash
   for i in account device mediaapi syncapi roomserver serverkey federationsender publicroomsapi naffka; do
@@ -69,6 +72,8 @@ Dendrite requires a postgres database engine, version 9.5 or later.
   done
   ```
 
+On macOS, omit `sudo -u postgres`.
+
 ### Crypto key generation
 
 Generate the keys: