diff --git a/Cargo.lock b/Cargo.lock
index 06a34742..1ef12819 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3567,6 +3567,7 @@ dependencies = [
  "sha1",
  "sha2",
  "spdx",
+ "strum",
  "tar",
  "tempfile",
  "terminal_size 0.4.0",
diff --git a/Cargo.toml b/Cargo.toml
index fb86f722..bef847c6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -143,6 +143,7 @@ rattler_solve = { version = "1.2.3", default-features = false, features = ["reso
 rattler_virtual_packages = { version = "1.1.10", default-features = false }
 rattler_package_streaming = { version = "0.22.13", default-features = false }
 lazy_static = "1.5.0"
+strum = "0.26.3"
 
 [dev-dependencies]
 insta = { version = "1.41.1", features = ["yaml"] }
diff --git a/src/recipe/jinja.rs b/src/recipe/jinja.rs
index 6745f04c..ca5ba1a1 100644
--- a/src/recipe/jinja.rs
+++ b/src/recipe/jinja.rs
@@ -399,6 +399,9 @@ fn set_jinja(config: &SelectorConfig) -> minijinja::Environment<'static> {
     } = config.clone();
 
     let mut env = Environment::empty();
+    if !allow_undefined {
+        env.set_undefined_behavior(minijinja::UndefinedBehavior::Strict);
+    }
     default_tests(&mut env);
     default_filters(&mut env);
 
diff --git a/src/selectors.rs b/src/selectors.rs
index f1347b6c..a79cf4b9 100644
--- a/src/selectors.rs
+++ b/src/selectors.rs
@@ -10,6 +10,7 @@ use crate::{
 
 use minijinja::value::Value;
 use rattler_conda_types::Platform;
+use strum::IntoEnumIterator;
 
 /// The selector config is used to render the recipe.
 #[derive(Clone, Debug)]
@@ -45,15 +46,20 @@ impl SelectorConfig {
             Value::from_safe_string(self.host_platform.to_string()),
         );
 
-        if let Some(platform) = self.host_platform.only_platform() {
-            context.insert(
-                platform.to_string(),
-                Value::from_safe_string(platform.to_string()),
-            );
-        }
-
-        if let Some(arch) = self.target_platform.arch() {
-            context.insert(arch.to_string(), Value::from(true));
+        for platform in Platform::iter() {
+            if let Some(only_platform) = platform.only_platform() {
+                context.insert(
+                    only_platform.to_string(),
+                    Value::from(self.host_platform == platform),
+                );
+            }
+
+            if let Some(arch) = platform.arch() {
+                context.insert(
+                    arch.to_string(),
+                    Value::from(self.host_platform.arch() == Some(arch)),
+                );
+            }
         }
 
         context.insert(
@@ -88,14 +94,22 @@ impl SelectorConfig {
 
     /// Create a new selector config from an existing one, replacing the variant
     pub fn with_variant(
-        &self,
+        self,
         variant: BTreeMap<NormalizedKey, String>,
         target_platform: Platform,
     ) -> Self {
         Self {
             variant,
             target_platform,
-            ..self.clone()
+            ..self
+        }
+    }
+
+    /// Set allow_undefined for this Jinja context / selector config
+    pub fn with_allow_undefined(self, allow_undefined: bool) -> Self {
+        Self {
+            allow_undefined,
+            ..self
         }
     }
 }
diff --git a/src/variant_render.rs b/src/variant_render.rs
index a952a892..7cc8fe0d 100644
--- a/src/variant_render.rs
+++ b/src/variant_render.rs
@@ -88,8 +88,9 @@ pub(crate) fn stage_0_render(
         let mut rendered_outputs = Vec::new();
         // TODO: figure out if we can pre-compute the `noarch` value.
         for output in outputs {
-            let config_with_variant =
-                selector_config.with_variant(combination.clone(), selector_config.target_platform);
+            let config_with_variant = selector_config
+                .clone()
+                .with_variant(combination.clone(), selector_config.target_platform);
 
             let parsed_recipe = Recipe::from_node(output, config_with_variant).map_err(|err| {
                 let errs: ParseErrors = err
@@ -381,7 +382,9 @@ pub(crate) fn stage_1_render(
             for (idx, output) in r.raw_outputs.vec.iter().enumerate() {
                 // use the correct target_platform here?
                 let config_with_variant = selector_config
-                    .with_variant(combination.clone(), selector_config.target_platform);
+                    .clone()
+                    .with_variant(combination.clone(), selector_config.target_platform)
+                    .with_allow_undefined(false);
 
                 let parsed_recipe = Recipe::from_node(output, config_with_variant.clone()).unwrap();