diff --git a/cranelift/codegen/src/isa/aarch64/inst/emit_tests.rs b/cranelift/codegen/src/isa/aarch64/inst/emit_tests.rs
index 915657c2f5..3d7016af2d 100644
--- a/cranelift/codegen/src/isa/aarch64/inst/emit_tests.rs
+++ b/cranelift/codegen/src/isa/aarch64/inst/emit_tests.rs
@@ -1,7 +1,6 @@
 use crate::ir::types::*;
 use crate::ir::TrapCode;
 use crate::isa::aarch64::inst::*;
-use crate::isa::test_utils;
 use crate::isa::CallConv;
 use crate::settings;
 
@@ -6523,12 +6522,10 @@ fn test_aarch64_binemit() {
         let actual_printing = insn.show_rru(Some(&rru));
         assert_eq!(expected_printing, actual_printing);
 
-        let mut sink = test_utils::TestCodeSink::new();
         let mut buffer = MachBuffer::new();
         insn.emit(&mut buffer, &emit_info, &mut Default::default());
         let buffer = buffer.finish();
-        buffer.emit(&mut sink);
-        let actual_encoding = &sink.stringify();
+        let actual_encoding = &buffer.stringify_code_bytes();
         assert_eq!(expected_encoding, actual_encoding);
     }
 }
diff --git a/cranelift/codegen/src/isa/arm32/inst/emit_tests.rs b/cranelift/codegen/src/isa/arm32/inst/emit_tests.rs
index 73269be999..421cc2e548 100644
--- a/cranelift/codegen/src/isa/arm32/inst/emit_tests.rs
+++ b/cranelift/codegen/src/isa/arm32/inst/emit_tests.rs
@@ -1,5 +1,4 @@
 use crate::isa::arm32::inst::*;
-use crate::isa::test_utils;
 use crate::settings;
 
 use alloc::vec::Vec;
@@ -1948,12 +1947,10 @@ fn test_arm32_emit() {
         // Check the printed text is as expected.
         let actual_printing = insn.show_rru(Some(&rru));
         assert_eq!(expected_printing, actual_printing);
-        let mut sink = test_utils::TestCodeSink::new();
         let mut buffer = MachBuffer::new();
         insn.emit(&mut buffer, &flags, &mut Default::default());
         let buffer = buffer.finish();
-        buffer.emit(&mut sink);
-        let actual_encoding = &sink.stringify();
+        let actual_encoding = &buffer.stringify_code_bytes();
         assert_eq!(expected_encoding, actual_encoding, "{}", expected_printing);
     }
 }
diff --git a/cranelift/codegen/src/isa/mod.rs b/cranelift/codegen/src/isa/mod.rs
index e92dc21627..f50cb83f9d 100644
--- a/cranelift/codegen/src/isa/mod.rs
+++ b/cranelift/codegen/src/isa/mod.rs
@@ -76,9 +76,6 @@ pub mod unwind;
 
 mod call_conv;
 
-#[cfg(test)]
-mod test_utils;
-
 /// Returns a builder that can create a corresponding `TargetIsa`
 /// or `Err(LookupError::SupportDisabled)` if not enabled.
 macro_rules! isa_builder {
diff --git a/cranelift/codegen/src/isa/s390x/inst/emit_tests.rs b/cranelift/codegen/src/isa/s390x/inst/emit_tests.rs
index 15f32bed74..9d60355fd1 100644
--- a/cranelift/codegen/src/isa/s390x/inst/emit_tests.rs
+++ b/cranelift/codegen/src/isa/s390x/inst/emit_tests.rs
@@ -1,7 +1,6 @@
 use crate::ir::MemFlags;
 use crate::isa::s390x::inst::*;
 use crate::isa::s390x::settings as s390x_settings;
-use crate::isa::test_utils;
 use crate::settings;
 use alloc::vec::Vec;
 
@@ -8112,12 +8111,10 @@ fn test_s390x_binemit() {
         let actual_printing = insn.show_rru(Some(&rru));
         assert_eq!(expected_printing, actual_printing);
 
-        let mut sink = test_utils::TestCodeSink::new();
         let mut buffer = MachBuffer::new();
         insn.emit(&mut buffer, &emit_info, &mut Default::default());
         let buffer = buffer.finish();
-        buffer.emit(&mut sink);
-        let actual_encoding = &sink.stringify();
+        let actual_encoding = &buffer.stringify_code_bytes();
         assert_eq!(expected_encoding, actual_encoding);
     }
 }
diff --git a/cranelift/codegen/src/isa/test_utils.rs b/cranelift/codegen/src/isa/test_utils.rs
deleted file mode 100644
index ed5eed09b4..0000000000
--- a/cranelift/codegen/src/isa/test_utils.rs
+++ /dev/null
@@ -1,74 +0,0 @@
-// This is unused when no platforms with the new backend are enabled.
-#![allow(dead_code)]
-
-use crate::binemit::{Addend, CodeOffset, CodeSink, Reloc};
-use crate::ir::{ExternalName, Opcode, SourceLoc, TrapCode};
-
-use alloc::vec::Vec;
-use std::string::String;
-
-pub struct TestCodeSink {
-    bytes: Vec<u8>,
-}
-
-impl TestCodeSink {
-    /// Create a new TestCodeSink.
-    pub fn new() -> TestCodeSink {
-        TestCodeSink { bytes: vec![] }
-    }
-
-    /// Return the code emitted to this sink as a hex string.
-    pub fn stringify(&self) -> String {
-        // This is pretty lame, but whatever ..
-        use std::fmt::Write;
-        let mut s = String::with_capacity(self.bytes.len() * 2);
-        for b in &self.bytes {
-            write!(&mut s, "{:02X}", b).unwrap();
-        }
-        s
-    }
-}
-
-impl CodeSink for TestCodeSink {
-    fn offset(&self) -> CodeOffset {
-        self.bytes.len() as CodeOffset
-    }
-
-    fn put1(&mut self, x: u8) {
-        self.bytes.push(x);
-    }
-
-    fn put2(&mut self, x: u16) {
-        self.bytes.push((x >> 0) as u8);
-        self.bytes.push((x >> 8) as u8);
-    }
-
-    fn put4(&mut self, mut x: u32) {
-        for _ in 0..4 {
-            self.bytes.push(x as u8);
-            x >>= 8;
-        }
-    }
-
-    fn put8(&mut self, mut x: u64) {
-        for _ in 0..8 {
-            self.bytes.push(x as u8);
-            x >>= 8;
-        }
-    }
-
-    fn reloc_external(
-        &mut self,
-        _srcloc: SourceLoc,
-        _rel: Reloc,
-        _name: &ExternalName,
-        _addend: Addend,
-    ) {
-    }
-
-    fn trap(&mut self, _code: TrapCode, _srcloc: SourceLoc) {}
-
-    fn end_codegen(&mut self) {}
-
-    fn add_call_site(&mut self, _opcode: Opcode, _srcloc: SourceLoc) {}
-}
diff --git a/cranelift/codegen/src/isa/x64/inst/emit_tests.rs b/cranelift/codegen/src/isa/x64/inst/emit_tests.rs
index acb335b80b..e8f905bcc5 100644
--- a/cranelift/codegen/src/isa/x64/inst/emit_tests.rs
+++ b/cranelift/codegen/src/isa/x64/inst/emit_tests.rs
@@ -13,7 +13,6 @@
 //!   -- isa::x64::inst::emit_tests::test_x64_emit
 
 use super::*;
-use crate::isa::test_utils;
 use crate::isa::x64;
 use alloc::vec::Vec;
 
@@ -4460,7 +4459,6 @@ fn test_x64_emit() {
         // Check the printed text is as expected.
         let actual_printing = insn.show_rru(Some(&rru));
         assert_eq!(expected_printing, actual_printing);
-        let mut sink = test_utils::TestCodeSink::new();
         let mut buffer = MachBuffer::new();
 
         insn.emit(&mut buffer, &emit_info, &mut Default::default());
@@ -4470,8 +4468,7 @@ fn test_x64_emit() {
         buffer.bind_label(label);
 
         let buffer = buffer.finish();
-        buffer.emit(&mut sink);
-        let actual_encoding = &sink.stringify();
+        let actual_encoding = &buffer.stringify_code_bytes();
         assert_eq!(expected_encoding, actual_encoding, "{}", expected_printing);
     }
 }
diff --git a/cranelift/codegen/src/machinst/buffer.rs b/cranelift/codegen/src/machinst/buffer.rs
index 298ee90cd1..87c2566e9e 100644
--- a/cranelift/codegen/src/machinst/buffer.rs
+++ b/cranelift/codegen/src/machinst/buffer.rs
@@ -1420,6 +1420,17 @@ impl MachBufferFinalized {
         self.data.len() as CodeOffset
     }
 
+    /// Return the code in this mach buffer as a hex string for testing purposes.
+    pub fn stringify_code_bytes(&self) -> String {
+        // This is pretty lame, but whatever ..
+        use std::fmt::Write;
+        let mut s = String::with_capacity(self.data.len() * 2);
+        for b in &self.data {
+            write!(&mut s, "{:02X}", b).unwrap();
+        }
+        s
+    }
+
     /// Emit this buffer to the given CodeSink.
     pub fn emit<CS: CodeSink>(&self, sink: &mut CS) {
         // N.B.: we emit every section into the .text section as far as