diff --git a/installing/installation-guide.md b/installing/installation-guide.md
index 1a2fbfec..761b5cb0 100644
--- a/installing/installation-guide.md
+++ b/installing/installation-guide.md
@@ -55,12 +55,12 @@ an installation medium.)
 If you prefer to use a USB drive, then you just need to copy the ISO onto the
 USB device, e.g. using `dd`:
 
-    dd if=Qubes-R3-x86_64.iso of=/dev/sdX
+    dd if=Qubes-R3-x86_64.iso of=/dev/sda
 
-Adjust the filename to the version you're installing. Make sure to use the entire device (e.g. use **/dev/sda** and not **/dev/sda1**)
-For example:
-
-    dd mif=Qubes-R3-x86_64.iso of=/dev/sda
+Change `Qubes-R3-x86_64.iso` to the filename of the version you're installing,
+and change `/dev/sda` to the correct target device. **Warning:** Choosing the
+wrong device could result in data loss. Make sure to write to the entire device
+(e.g., `/dev/sda`) rather than just a single partition (e.g., `/dev/sda1`).
 
 On Windows, you can use the [Rufus] tool. Be sure to select "DD image" mode (you
 need to do that **after** selecting the Qubes ISO):