diff --git a/.gitmodules b/.gitmodules
index 984113151de4d..40e6fc2c19db0 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -37,7 +37,7 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
 	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/11.0-2020-10-12
+	branch = rustc/11.0-2021-01-05
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book
 	url = https://github.com/rust-embedded/book.git
diff --git a/src/llvm-project b/src/llvm-project
index fb115ee43b776..f9a8d70b6e036 160000
--- a/src/llvm-project
+++ b/src/llvm-project
@@ -1 +1 @@
-Subproject commit fb115ee43b77601b237717c21ab0a8f5b5b9d50a
+Subproject commit f9a8d70b6e0365ac2172ca6b7f1de0341297458d
diff --git a/src/test/ui/extern/extern-compare-with-return-type.rs b/src/test/ui/extern/extern-compare-with-return-type.rs
index 6c9ed3760f6e4..52b51bb943aa6 100644
--- a/src/test/ui/extern/extern-compare-with-return-type.rs
+++ b/src/test/ui/extern/extern-compare-with-return-type.rs
@@ -2,8 +2,9 @@
 // Tests that we can compare various kinds of extern fn signatures.
 #![allow(non_camel_case_types)]
 
-extern fn voidret1() {}
-extern fn voidret2() {}
+// `dbg!()` differentiates these functions to ensure they won't be merged.
+extern fn voidret1() { dbg!() }
+extern fn voidret2() { dbg!() }
 
 extern fn uintret() -> usize { 22 }