diff --git a/src/main.rs b/src/main.rs
index 0a31a8b7..ca73d0e3 100755
--- a/src/main.rs
+++ b/src/main.rs
@@ -204,7 +204,10 @@ fn run() -> Result<()> {
                 .long("base-address-shift")
                 .alias("base_address_shift")
                 .action(ArgAction::Set)
-                .help("Shift base address for all peripherals"),
+                .help("Add offset to all base addresses on all peripherals in the SVD file.")
+                .long_help("Add offset to all base addresses on all peripherals in the SVD file.
+Useful for soft-cores where the peripheral address range isn't necessarily fixed.
+Ignore this option if you are not building your own FPGA based soft-cores."),
         )
         .arg(
             Arg::new("log_level")