diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 28f18dffd2..8d3f4d5273 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -107,6 +107,12 @@ jobs:
     - run: cargo check --target wasm32-unknown-emscripten -p wasi-common
     - run: cargo check --target armv7-unknown-linux-gnueabihf -p wasi-common
 
+    # Check that codegen and wasm crates typecheck on 1.41.0; this is required
+    # for Firefox.
+    - run: rustup install 1.41.0
+    - run: cargo +1.41.0 check -p cranelift-codegen
+    - run: cargo +1.41.0 check -p cranelift-wasm
+
 
   fuzz_targets:
     name: Fuzz Targets
diff --git a/cranelift/codegen/src/abi.rs b/cranelift/codegen/src/abi.rs
index 0da415b5ce..cf4780e353 100644
--- a/cranelift/codegen/src/abi.rs
+++ b/cranelift/codegen/src/abi.rs
@@ -80,7 +80,10 @@ impl ValueConversion {
 
     /// Is this a conversion to pointer?
     pub fn is_pointer(self) -> bool {
-        matches!(self, Self::Pointer(_))
+        match self {
+            Self::Pointer(_) => true,
+            _ => false,
+        }
     }
 }
 
diff --git a/cranelift/codegen/src/ir/instructions.rs b/cranelift/codegen/src/ir/instructions.rs
index 653926a242..6354b92580 100644
--- a/cranelift/codegen/src/ir/instructions.rs
+++ b/cranelift/codegen/src/ir/instructions.rs
@@ -311,7 +311,7 @@ impl InstructionData {
                 arg: _,
                 imm,
             } => {
-                if matches!(opcode, Opcode::SdivImm | Opcode::SremImm) {
+                if *opcode == Opcode::SdivImm || *opcode == Opcode::SremImm {
                     imm.sign_extend_from_width(bit_width);
                 }
             }