diff --git a/pkgs/top-level/platforms.nix b/pkgs/top-level/platforms.nix
index 1e2bb4b1ec7d..14d4f87d2855 100644
--- a/pkgs/top-level/platforms.nix
+++ b/pkgs/top-level/platforms.nix
@@ -50,6 +50,9 @@ rec {
         EXT4_FS m
         USB_STORAGE_CYPRESS_ATACB m
 
+        # mv cesa requires this sw fallback, for mv-sha1
+        CRYPTO_SHA1 y
+
         IP_PNP y
         IP_PNP_DHCP y
         NFS_FS y