diff --git a/azalea/build.rs b/azalea/build.rs
index f97dce653..25fff0e59 100644
--- a/azalea/build.rs
+++ b/azalea/build.rs
@@ -1,8 +1,24 @@
 use std::env;
+use std::process::Command;
 
 fn main() {
-    let rust_toolchain = env::var("RUSTUP_TOOLCHAIN").unwrap();
-    if rust_toolchain.starts_with("stable") {
-        panic!("Azalea currently requires nightly Rust. You can use `rustup override set nightly` to set the toolchain for this directory.");
+    match env::var("RUSTUP_TOOLCHAIN") {
+        Ok(rust_toolchain) if !rust_toolchain.starts_with("nightly")  => { // stable & beta
+            panic!("Azalea currently requires nightly Rust. You can use `rustup override set nightly` to set the toolchain for this directory.");
+        }
+        Ok(_) => return, // nightly
+        Err(_) => { // probably not installed via rustup, run rustc and parse its output
+            let rustc_command = env::var("RUSTC")
+                .or_else(|_| env::var("CARGO_BUILD_RUSTC"))
+                .unwrap_or(String::from("rustc"));
+            let rustc_version_output = Command::new(rustc_command).arg("-V").output().unwrap();
+            if !rustc_version_output.status.success()
+                || !String::from_utf8(rustc_version_output.stdout)
+                    .unwrap()
+                    .contains("nightly")
+            {
+                panic!("Azalea currently requires nightly Rust. It seems that you did not install Rust via rustup. Please check the documentation for your installation method, to find out how to use nightly Rust.");
+            }
+        }
     }
 }