diff --git a/crates/uv-dispatch/src/lib.rs b/crates/uv-dispatch/src/lib.rs
index ddc2d5ed5..606836a06 100644
--- a/crates/uv-dispatch/src/lib.rs
+++ b/crates/uv-dispatch/src/lib.rs
@@ -175,7 +175,7 @@ impl<'a> BuildDispatch<'a> {
 impl BuildContext for BuildDispatch<'_> {
     type SourceDistBuilder = SourceBuild;
 
-    fn interpreter(&self) -> &Interpreter {
+    async fn interpreter(&self) -> &Interpreter {
         self.interpreter
     }
 
diff --git a/crates/uv-distribution/src/source/mod.rs b/crates/uv-distribution/src/source/mod.rs
index f269c1b87..3d9361797 100644
--- a/crates/uv-distribution/src/source/mod.rs
+++ b/crates/uv-distribution/src/source/mod.rs
@@ -2386,11 +2386,13 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
             let base_python = if cfg!(unix) {
                 self.build_context
                     .interpreter()
+                    .await
                     .find_base_python()
                     .map_err(Error::BaseInterpreter)?
             } else {
                 self.build_context
                     .interpreter()
+                    .await
                     .to_base_python()
                     .map_err(Error::BaseInterpreter)?
             };
@@ -2485,7 +2487,7 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
         // Ensure that the _installed_ Python version is compatible with the `requires-python`
         // specifier.
         if let Some(requires_python) = source.requires_python() {
-            let installed = self.build_context.interpreter().python_version();
+            let installed = self.build_context.interpreter().await.python_version();
             let target = release_specifiers_to_ranges(requires_python.clone())
                 .bounding_range()
                 .map(|bounding_range| bounding_range.0.cloned())
@@ -2507,11 +2509,13 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
         let base_python = if cfg!(unix) {
             self.build_context
                 .interpreter()
+                .await
                 .find_base_python()
                 .map_err(Error::BaseInterpreter)?
         } else {
             self.build_context
                 .interpreter()
+                .await
                 .to_base_python()
                 .map_err(Error::BaseInterpreter)?
         };
diff --git a/crates/uv-types/src/traits.rs b/crates/uv-types/src/traits.rs
index 875742da9..68e6583ae 100644
--- a/crates/uv-types/src/traits.rs
+++ b/crates/uv-types/src/traits.rs
@@ -62,8 +62,10 @@ use crate::BuildArena;
 pub trait BuildContext {
     type SourceDistBuilder: SourceBuildTrait;
 
+    // Note: this function is async deliberately, because downstream code may need to
+    // run async code to get the interpreter, to resolve the Python version.
     /// Return a reference to the interpreter.
-    fn interpreter(&self) -> &Interpreter;
+    fn interpreter(&self) -> impl Future<Output = &Interpreter> + '_;
 
     /// Return a reference to the cache.
     fn cache(&self) -> &Cache;