diff --git a/plugins/by-name/otter/default.nix b/plugins/by-name/otter/default.nix
index fd841b83..34feed28 100644
--- a/plugins/by-name/otter/default.nix
+++ b/plugins/by-name/otter/default.nix
@@ -12,6 +12,10 @@ lib.nixvim.plugins.mkNeovimPlugin {
 
   maintainers = [ lib.maintainers.HeitorAugustoLN ];
 
+  # `require("otter").setup()` must run **BEFORE** quarto
+  # https://github.com/quarto-dev/quarto-nvim/issues/187
+  configLocation = lib.mkOrder 900 "extraConfigLua";
+
   imports = [
     # TODO: introduced 2024-06-29; remove after 24.11
     (lib.mkRemovedOptionModule
diff --git a/plugins/by-name/quarto/default.nix b/plugins/by-name/quarto/default.nix
index 50413eae..77c628d0 100644
--- a/plugins/by-name/quarto/default.nix
+++ b/plugins/by-name/quarto/default.nix
@@ -1,4 +1,4 @@
-{ lib, pkgs, ... }:
+{ lib, config, ... }:
 let
   inherit (lib.nixvim) defaultNullOpts;
   inherit (lib) types;
@@ -99,4 +99,13 @@ lib.nixvim.plugins.mkNeovimPlugin {
       default_method = "vim-slime";
     };
   };
+
+  extraConfig = cfg: {
+    assertions = lib.nixvim.mkAssertions "plugins.quarto" {
+      assertion = (cfg.settings.codeRunner.enable or false) -> config.plugins.otter.enable;
+      message = ''
+        Quarto requires `plugins.otter` to be enabled when `settings.codeRunner.enable` is true.
+      '';
+    };
+  };
 }
diff --git a/tests/test-sources/plugins/by-name/quarto/default.nix b/tests/test-sources/plugins/by-name/quarto/default.nix
index 45d036d1..d28c1837 100644
--- a/tests/test-sources/plugins/by-name/quarto/default.nix
+++ b/tests/test-sources/plugins/by-name/quarto/default.nix
@@ -1,6 +1,13 @@
 {
   empty = {
-    plugins.quarto.enable = true;
+    plugins = {
+      quarto.enable = true;
+      otter.enable = true;
+      treesitter = {
+        enable = true;
+        settings.highlight.enable = true;
+      };
+    };
   };
 
   defaults = {
@@ -39,36 +46,44 @@
   };
 
   example = {
-    plugins.quarto = {
-      enable = true;
+    plugins = {
+      otter.enable = true;
+      treesitter = {
+        enable = true;
+        settings.highlight.enable = true;
+      };
 
-      settings = {
-        debug = true;
-        closePreviewOnExit = false;
-        lspFeatures = {
-          enabled = true;
-          chunks = "curly";
-          languages = [
-            "r"
-            "python"
-            "julia"
-          ];
-          diagnostics = {
+      quarto = {
+        enable = true;
+
+        settings = {
+          debug = true;
+          closePreviewOnExit = false;
+          lspFeatures = {
             enabled = true;
-            triggers = [ "BufWritePost" ];
+            chunks = "curly";
+            languages = [
+              "r"
+              "python"
+              "julia"
+            ];
+            diagnostics = {
+              enabled = true;
+              triggers = [ "BufWritePost" ];
+            };
+            completion = {
+              enabled = true;
+            };
           };
-          completion = {
+          codeRunner = {
             enabled = true;
+            default_method = "molten";
+            ft_runners = {
+              python = "molten";
+            };
+            never_run = [ "yaml" ];
           };
         };
-        codeRunner = {
-          enabled = true;
-          default_method = "molten";
-          ft_runners = {
-            python = "molten";
-          };
-          never_run = [ "yaml" ];
-        };
       };
     };
   };