diff --git a/README.md b/README.md
index 8b0e56d..7fa1670 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,9 @@ which was in turn derived from the Raspbian project.
 **Note**: Raspberry Pi OS 32 bit images are based primarily on Raspbian, while
 Raspberry Pi OS 64 bit images are based primarily on Debian.
 
+**Note**: 32 bit images should be built from the `master` branch.
+64 bit images should be built from the `arm64` branch.
+
 ## Dependencies
 
 pi-gen runs on Debian-based operating systems released after 2017, and we
@@ -152,7 +155,7 @@ The following environment variables are supported:
 
  * `TIMEZONE_DEFAULT` (Default: 'Europe/London' )
 
-   Default keyboard layout.
+   Default time zone.
 
    To get the current value from a running system, look in
    `/etc/timezone`.
diff --git a/build.sh b/build.sh
index f051727..4d55b52 100755
--- a/build.sh
+++ b/build.sh
@@ -255,18 +255,24 @@ trap term EXIT INT TERM
 
 dependencies_check "${BASE_DIR}/depends"
 
+
+PAGESIZE=$(getconf PAGESIZE)
+if [ "$ARCH" == "armhf" ] && [ "$PAGESIZE" != "4096" ]; then
+	echo
+	echo "ERROR: Building an $ARCH image requires a kernel with a 4k page size (current: $PAGESIZE)"
+	echo "On Raspberry Pi OS (64-bit), you can switch to a suitable kernel by adding the following to /boot/firmware/config.txt and rebooting:"
+	echo
+	echo "kernel=kernel8.img"
+	echo "initramfs initramfs8 followkernel"
+	echo
+	exit 1
+fi
+
 echo "Checking native $ARCH executable support..."
 if ! arch-test -n "$ARCH"; then
 	echo "WARNING: Only a native build environment is supported. Checking emulated support..."
 	if ! arch-test "$ARCH"; then
 		echo "No fallback mechanism found. Ensure your OS has binfmt_misc support enabled and configured."
-		PAGESIZE=$(getconf PAGESIZE)
-		if [ "$ARCH" == "armhf" ] && [ "$PAGESIZE" != "4096" ]; then
-			echo
-			echo "Building an $ARCH image requires a kernel with a 4k page size"
-			echo "Current pagesize: $PAGESIZE"
-			echo "On Raspberry Pi OS, you can switch to a suitable kernel by adding kernel=kernel8.img to /boot/firmware/config.txt and rebooting"
-		fi
 		exit 1
 	fi
 fi