diff --git a/build.rs b/build.rs
index 47ea958..f9acb3a 100644
--- a/build.rs
+++ b/build.rs
@@ -627,6 +627,15 @@ fn set_python_path(distribution_source: &str) {
     } else {
         set_runtime_variable(installation_variable, "bin/python3");
     };
+
+    let installation_variable_pythonw = "PYAPP__INSTALLATION_PYTHONW_PATH";
+    if is_enabled("PYAPP_FULL_ISOLATION") {
+        set_runtime_variable(installation_variable_pythonw, &relative_path);
+    } else if on_windows {
+        set_runtime_variable(installation_variable_pythonw, r"Scripts\pythonw.exe");
+    } else {
+        set_runtime_variable(installation_variable_pythonw, "bin/python3");
+    };
 }
 
 fn set_site_packages_path(distribution_source: &str) {