diff --git a/hosts/by-name/moby/default.nix b/hosts/by-name/moby/default.nix
index 042a4ade0..e8de23bcf 100644
--- a/hosts/by-name/moby/default.nix
+++ b/hosts/by-name/moby/default.nix
@@ -38,6 +38,9 @@
 
   sane.gui.sxmo.enable = true;
   sane.services.eg25-manager.enable = true;
+  # i only need eg25-manager for GPS purposes;
+  # but modemmanager outright fails -- blocking eg25-manager -- unless i provide it a sim.
+  sane.services.eg25-manager.package = pkgs.eg25-manager.override { withModemManager = false; };
   sane.programs.guiApps.suggestedPrograms = [ "handheldGuiApps" ];
   # sane.programs.consoleUtils.enableFor.user.colin = false;
   # sane.programs.guiApps.enableFor.user.colin = false;
diff --git a/modules/services/eg25-manager.nix b/modules/services/eg25-manager.nix
index d4f1536ae..07f997dc1 100644
--- a/modules/services/eg25-manager.nix
+++ b/modules/services/eg25-manager.nix
@@ -12,20 +12,25 @@ let
   '';
 in
 {
-  options.sane.services.eg25-manager = {
-    enable = lib.mkEnableOption "Quectel EG25 modem manager service";
+  options.sane.services.eg25-manager = with lib; {
+    enable = mkEnableOption "Quectel EG25 modem manager service";
+    package = mkOption {
+      type = types.package;
+      default = pkgs.eg25-manager;
+    };
   };
   config = lib.mkIf cfg.enable {
     # eg25-manager package ships udev rules *and* a systemd service.
     # for that reason, i think it needs to be on the system path for the systemd service to be enabled.
-    services.udev.packages = [ pkgs.eg25-manager ];
+    services.udev.packages = [ cfg.package ];
 
     # but actually, let's define our own systemd service so that we can control config
     systemd.services.eg25-manager = {
       serviceConfig = {
         Type = "simple";
-        ExecStart = "${pkgs.eg25-manager}/bin/eg25-manager --config ${eg25-config-toml}";
+        ExecStart = "${cfg.package}/bin/eg25-manager --config ${eg25-config-toml}";
         ExecStartPre = pkgs.writeShellScript "unload-modem-power" ''
+          # see issue: <https://gitlab.com/mobian1/eg25-manager/-/issues/38>
           ${pkgs.kmod}/bin/modprobe -r modem_power && echo "WARNING: kernel configured with CONFIG_MODEM_POWER=y, may be incompatible with eg25-manager" || true
         '';
 
diff --git a/pkgs/additional/eg25-manager/default.nix b/pkgs/additional/eg25-manager/default.nix
index 7e5db5140..df2fc6848 100644
--- a/pkgs/additional/eg25-manager/default.nix
+++ b/pkgs/additional/eg25-manager/default.nix
@@ -14,7 +14,8 @@
 , glib
 , libgudev
 , libusb1
-, modemmanager
+# if true, build with MMGLIB. if false, eg25-manager won't speak to modemmanager and will be usable standalone
+, withModemManager ? true, modemmanager
 }:
 
 let
@@ -59,6 +60,7 @@ stdenv.mkDerivation rec {
     libgpiod1
     libgudev
     libusb1
+  ] ++ lib.optionals withModemManager [
     modemmanager
   ];