diff --git a/changelog.md b/changelog.md
index ecbe31614a5..cccabecde24 100644
--- a/changelog.md
+++ b/changelog.md
@@ -6,6 +6,7 @@
 - Support both owned and borrowed blacklisted crate names in `rls-analysis`
 - Publicly re-export `rls_analysis::raw::Crate`
 ### Changed
+- Formatting project files now only needs project to parse and expand macros (and not type-check)
 - Converted remaining crates `rls-*` to 2018 edition
 ### Removed
 - Removed `use_crate_blacklist` setting in favour of `crate_blacklist`
diff --git a/rls/src/build/rustc.rs b/rls/src/build/rustc.rs
index 43c33daf990..27bb6354003 100644
--- a/rls/src/build/rustc.rs
+++ b/rls/src/build/rustc.rs
@@ -166,7 +166,7 @@ impl rustc_driver::Callbacks for RlsRustcCalls {
         Compilation::Continue
     }
 
-    fn after_analysis(&mut self, compiler: &interface::Compiler) -> Compilation {
+    fn after_expansion(&mut self, compiler: &interface::Compiler) -> Compilation {
         let sess = compiler.session();
         let input = compiler.input();
         let crate_name = compiler.crate_name().unwrap().peek().clone();
@@ -189,11 +189,20 @@ impl rustc_driver::Callbacks for RlsRustcCalls {
             },
         };
 
+        // We populate the file -> edition mapping only after expansion since it
+        // can pull additional input files
         let mut input_files = self.input_files.lock().unwrap();
         for file in fetch_input_files(sess) {
             input_files.entry(file).or_default().insert(krate.clone());
         }
 
+        Compilation::Continue
+    }
+
+    fn after_analysis(&mut self, compiler: &interface::Compiler) -> Compilation {
+        let input = compiler.input();
+        let crate_name = compiler.crate_name().unwrap().peek().clone();
+
         // Guaranteed to not be dropped yet in the pipeline thanks to the
         // `config.opts.debugging_opts.save_analysis` value being set to `true`.
         let expanded_crate = &compiler.expansion().unwrap().peek().0;