diff --git a/tests/run-make/autodiff/type-trees/array-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/array-typetree/rmake.rs
index 20b6a0669062..41805d26c6f7 100644
--- a/tests/run-make/autodiff/type-trees/array-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/array-typetree/rmake.rs
@@ -4,6 +4,6 @@
 use run_make_support::{llvm_filecheck, rfs, rustc};
 
 fn main() {
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
     llvm_filecheck().patterns("array.check").stdin_buf(rfs::read("test.ll")).run();
 }
diff --git a/tests/run-make/autodiff/type-trees/mixed-struct-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/mixed-struct-typetree/rmake.rs
index 1c19963bc361..d740596907a3 100644
--- a/tests/run-make/autodiff/type-trees/mixed-struct-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/mixed-struct-typetree/rmake.rs
@@ -9,6 +9,7 @@ fn main() {
         .arg("-Zautodiff=Enable")
         .arg("-Zautodiff=NoPostopt")
         .opt_level("0")
+        .arg("-Clto=fat")
         .emit("llvm-ir")
         .run();
 
diff --git a/tests/run-make/autodiff/type-trees/nott-flag/rmake.rs b/tests/run-make/autodiff/type-trees/nott-flag/rmake.rs
index de540b990cab..2e93d586a353 100644
--- a/tests/run-make/autodiff/type-trees/nott-flag/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/nott-flag/rmake.rs
@@ -8,6 +8,7 @@ fn main() {
     rustc()
         .input("test.rs")
         .arg("-Zautodiff=Enable,NoTT")
+        .arg("-Clto=fat")
         .emit("llvm-ir")
         .arg("-o")
         .arg("nott.ll")
@@ -17,6 +18,7 @@ fn main() {
     rustc()
         .input("test.rs")
         .arg("-Zautodiff=Enable")
+        .arg("-Clto=fat")
         .emit("llvm-ir")
         .arg("-o")
         .arg("with_tt.ll")
diff --git a/tests/run-make/autodiff/type-trees/recursion-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/recursion-typetree/rmake.rs
index 78718f3a2159..af1eb4197b3b 100644
--- a/tests/run-make/autodiff/type-trees/recursion-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/recursion-typetree/rmake.rs
@@ -4,6 +4,6 @@
 use run_make_support::{llvm_filecheck, rfs, rustc};
 
 fn main() {
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
     llvm_filecheck().patterns("recursion.check").stdin_buf(rfs::read("test.ll")).run();
 }
diff --git a/tests/run-make/autodiff/type-trees/scalar-types/f128-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/scalar-types/f128-typetree/rmake.rs
index 44320ecdd571..b1672cddb811 100644
--- a/tests/run-make/autodiff/type-trees/scalar-types/f128-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/scalar-types/f128-typetree/rmake.rs
@@ -5,7 +5,7 @@
 
 fn main() {
     // Compile with TypeTree enabled and emit LLVM IR
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
 
     // Check that f128 TypeTree metadata is correctly generated
     llvm_filecheck().patterns("f128.check").stdin_buf(rfs::read("test.ll")).run();
diff --git a/tests/run-make/autodiff/type-trees/scalar-types/f16-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/scalar-types/f16-typetree/rmake.rs
index 0aebdbf55209..3e308a91aaff 100644
--- a/tests/run-make/autodiff/type-trees/scalar-types/f16-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/scalar-types/f16-typetree/rmake.rs
@@ -5,7 +5,7 @@
 
 fn main() {
     // Compile with TypeTree enabled and emit LLVM IR
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
 
     // Check that f16 TypeTree metadata is correctly generated
     llvm_filecheck().patterns("f16.check").stdin_buf(rfs::read("test.ll")).run();
diff --git a/tests/run-make/autodiff/type-trees/scalar-types/f32-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/scalar-types/f32-typetree/rmake.rs
index ee3ab753bf50..3faba69f5bdd 100644
--- a/tests/run-make/autodiff/type-trees/scalar-types/f32-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/scalar-types/f32-typetree/rmake.rs
@@ -5,7 +5,7 @@
 
 fn main() {
     // Compile with TypeTree enabled and emit LLVM IR
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
 
     // Check that f32 TypeTree metadata is correctly generated
     llvm_filecheck().patterns("f32.check").stdin_buf(rfs::read("test.ll")).run();
diff --git a/tests/run-make/autodiff/type-trees/scalar-types/f64-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/scalar-types/f64-typetree/rmake.rs
index 5fac9b23bc80..4f1c2cec51c4 100644
--- a/tests/run-make/autodiff/type-trees/scalar-types/f64-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/scalar-types/f64-typetree/rmake.rs
@@ -5,7 +5,7 @@
 
 fn main() {
     // Compile with TypeTree enabled and emit LLVM IR
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
 
     // Check that f64 TypeTree metadata is correctly generated
     llvm_filecheck().patterns("f64.check").stdin_buf(rfs::read("test.ll")).run();
diff --git a/tests/run-make/autodiff/type-trees/scalar-types/i32-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/scalar-types/i32-typetree/rmake.rs
index a40fd55d88ad..328d690f29c8 100644
--- a/tests/run-make/autodiff/type-trees/scalar-types/i32-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/scalar-types/i32-typetree/rmake.rs
@@ -5,7 +5,7 @@
 
 fn main() {
     // Compile with TypeTree enabled and emit LLVM IR
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
 
     // Check that i32 TypeTree metadata is correctly generated
     llvm_filecheck().patterns("i32.check").stdin_buf(rfs::read("test.ll")).run();
diff --git a/tests/run-make/autodiff/type-trees/slice-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/slice-typetree/rmake.rs
index b81fb50bf1a7..0cc6b42a0317 100644
--- a/tests/run-make/autodiff/type-trees/slice-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/slice-typetree/rmake.rs
@@ -4,6 +4,6 @@
 use run_make_support::{llvm_filecheck, rfs, rustc};
 
 fn main() {
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
     llvm_filecheck().patterns("slice.check").stdin_buf(rfs::read("test.ll")).run();
 }
diff --git a/tests/run-make/autodiff/type-trees/struct-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/struct-typetree/rmake.rs
index 0af1b65ee181..10499712d1e3 100644
--- a/tests/run-make/autodiff/type-trees/struct-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/struct-typetree/rmake.rs
@@ -4,6 +4,6 @@
 use run_make_support::{llvm_filecheck, rfs, rustc};
 
 fn main() {
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
     llvm_filecheck().patterns("struct.check").stdin_buf(rfs::read("test.ll")).run();
 }
diff --git a/tests/run-make/autodiff/type-trees/tuple-typetree/rmake.rs b/tests/run-make/autodiff/type-trees/tuple-typetree/rmake.rs
index 76913828901c..4c0458f588a8 100644
--- a/tests/run-make/autodiff/type-trees/tuple-typetree/rmake.rs
+++ b/tests/run-make/autodiff/type-trees/tuple-typetree/rmake.rs
@@ -4,6 +4,6 @@
 use run_make_support::{llvm_filecheck, rfs, rustc};
 
 fn main() {
-    rustc().input("test.rs").arg("-Zautodiff=Enable").emit("llvm-ir").run();
+    rustc().input("test.rs").arg("-Zautodiff=Enable").arg("-Clto=fat").emit("llvm-ir").run();
     llvm_filecheck().patterns("tuple.check").stdin_buf(rfs::read("test.ll")).run();
 }