diff --git a/third_party/nix/meson.build b/third_party/nix/meson.build
index 50d4dfc0c..9e20c499f 100644
--- a/third_party/nix/meson.build
+++ b/third_party/nix/meson.build
@@ -474,9 +474,10 @@ endif
 
 # Look for libsodium, an optional dependency.
 #--------------------------------------------------
-if (get_option('with_libsodium'))
+libsodium_lib = cpp.find_library('sodium', required: get_option('with_libsodium'))
+if (libsodium_lib.found())
     libsodium_dep = declare_dependency(
-        dependencies : cpp.find_library('sodium'),
+        dependencies : libsodium_lib,
         link_args :  get_option('sodium_link_args'))
     config_h.set('HAVE_SODIUM', 1, description : 'Whether to use libsodium for cryptography.')
 else
diff --git a/third_party/nix/meson_options.txt b/third_party/nix/meson_options.txt
index 9bad1b2c4..8d8e5dab5 100644
--- a/third_party/nix/meson_options.txt
+++ b/third_party/nix/meson_options.txt
@@ -153,8 +153,8 @@ option(
 
 option(
     'with_libsodium',
-    type : 'boolean',
-    value : 'true',
+    type : 'feature',
+    value : 'auto',
     description : 'build nix with shared libs')
 
 option(