diff --git a/locales/en-US.ftl b/locales/en-US.ftl
new file mode 100644
index 00000000000..6101b28ab0c
--- /dev/null
+++ b/locales/en-US.ftl
@@ -0,0 +1,62 @@
+codegen_gcc_unwinding_inline_asm =
+    GCC backend does not support unwinding from inline asm
+
+codegen_gcc_lto_not_supported =
+    LTO is not supported. You may get a linker error.
+
+codegen_gcc_invalid_monomorphization_basic_integer =
+    invalid monomorphization of `{$name}` intrinsic: expected basic integer type, found `{$ty}`
+
+codegen_gcc_invalid_monomorphization_invalid_float_vector =
+    invalid monomorphization of `{$name}` intrinsic: unsupported element type `{$elem_ty}` of floating-point vector `{$vec_ty}`
+
+codegen_gcc_invalid_monomorphization_not_float =
+    invalid monomorphization of `{$name}` intrinsic: `{$ty}` is not a floating-point type
+
+codegen_gcc_invalid_monomorphization_unrecognized =
+    invalid monomorphization of `{$name}` intrinsic: unrecognized intrinsic `{$name}`
+
+codegen_gcc_invalid_monomorphization_expected_signed_unsigned =
+    invalid monomorphization of `{$name}` intrinsic: expected element type `{$elem_ty}` of vector type `{$vec_ty}` to be a signed or unsigned integer type
+
+codegen_gcc_invalid_monomorphization_unsupported_element =
+    invalid monomorphization of `{$name}` intrinsic: unsupported {$name} from `{$in_ty}` with element `{$elem_ty}` to `{$ret_ty}`
+
+codegen_gcc_invalid_monomorphization_invalid_bitmask =
+    invalid monomorphization of `{$name}` intrinsic: invalid bitmask `{$ty}`, expected `u{$expected_int_bits}` or `[u8; {$expected_bytes}]`
+
+codegen_gcc_invalid_monomorphization_simd_shuffle =
+    invalid monomorphization of `{$name}` intrinsic: simd_shuffle index must be an array of `u32`, got `{$ty}`
+
+codegen_gcc_invalid_monomorphization_expected_simd =
+    invalid monomorphization of `{$name}` intrinsic: expected SIMD {$expected_ty} type, found non-SIMD `{$found_ty}`
+
+codegen_gcc_invalid_monomorphization_mask_type =
+    invalid monomorphization of `{$name}` intrinsic: mask element type is `{$ty}`, expected `i_`
+
+codegen_gcc_invalid_monomorphization_return_length =
+    invalid monomorphization of `{$name}` intrinsic: expected return type of length {$in_len}, found `{$ret_ty}` with length {$out_len}
+
+codegen_gcc_invalid_monomorphization_return_length_input_type =
+    invalid monomorphization of `{$name}` intrinsic: expected return type with length {$in_len} (same as input type `{$in_ty}`), found `{$ret_ty}` with length {$out_len}
+
+codegen_gcc_invalid_monomorphization_return_element =
+    invalid monomorphization of `{$name}` intrinsic: expected return element type `{$in_elem}` (element of input `{$in_ty}`), found `{$ret_ty}` with element type `{$out_ty}`
+
+codegen_gcc_invalid_monomorphization_return_type =
+    invalid monomorphization of `{$name}` intrinsic: expected return type `{$in_elem}` (element of input `{$in_ty}`), found `{$ret_ty}`
+
+codegen_gcc_invalid_monomorphization_inserted_type =
+    invalid monomorphization of `{$name}` intrinsic: expected inserted type `{$in_elem}` (element of input `{$in_ty}`), found `{$out_ty}`
+
+codegen_gcc_invalid_monomorphization_return_integer_type =
+    invalid monomorphization of `{$name}` intrinsic: expected return type with integer elements, found `{$ret_ty}` with non-integer `{$out_ty}`
+
+codegen_gcc_invalid_monomorphization_mismatched_lengths =
+    invalid monomorphization of `{$name}` intrinsic: mismatched lengths: mask length `{$m_len}` != other vector length `{$v_len}`
+
+codegen_gcc_invalid_monomorphization_unsupported_cast =
+    invalid monomorphization of `{$name}` intrinsic: unsupported cast from `{$in_ty}` with element `{$in_elem}` to `{$ret_ty}` with element `{$out_elem}`
+
+codegen_gcc_invalid_monomorphization_unsupported_operation =
+    invalid monomorphization of `{$name}` intrinsic: unsupported operation on `{$in_ty}` with element `{$in_elem}`
diff --git a/src/lib.rs b/src/lib.rs
index 5ab87feb98b..546c892aae5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -73,7 +73,8 @@
 use rustc_codegen_ssa::target_features::supported_target_features;
 use rustc_codegen_ssa::traits::{CodegenBackend, ExtraBackendMethods, ModuleBufferMethods, ThinBufferMethods, WriteBackendMethods};
 use rustc_data_structures::fx::FxHashMap;
-use rustc_errors::{ErrorGuaranteed, Handler};
+use rustc_errors::{DiagnosticMessage, ErrorGuaranteed, Handler, SubdiagnosticMessage};
+use rustc_macros::fluent_messages;
 use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::ty::TyCtxt;
@@ -84,6 +85,8 @@
 use rustc_span::fatal_error::FatalError;
 use tempfile::TempDir;
 
+fluent_messages! { "../locales/en-US.ftl" }
+
 pub struct PrintOnPanic<F: Fn() -> String>(pub F);
 
 impl<F: Fn() -> String> Drop for PrintOnPanic<F> {