diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c0e9ae33..92c13619 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,23 @@ on: [push, pull_request]
 #   May require a special support for build-only mode in btest
 
 jobs:
+  ubuntu-aarch64-host:
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Install Rust
+        run: rustup toolchain install stable --no-self-update --profile minimal
+      - name: Install Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -qq -y clang make
+      - name: Build Toolchain
+        run: |
+          make -B
+      - name: Run Tests
+        run: |
+          ./build/btest -t gas-aarch64-linux
   ubuntu-linux-windows:
     runs-on: ubuntu-latest
     steps:
diff --git a/src/codegen/mos6502.rs b/src/codegen/mos6502.rs
index 57114c8b..e877e88f 100644
--- a/src/codegen/mos6502.rs
+++ b/src/codegen/mos6502.rs
@@ -505,10 +505,10 @@ pub unsafe fn parse_addr_or_label(line_begin: *const c_char, mut line: *const c_
                                   asm: *mut Assembler) -> (Address, *const c_char) {
     while isspace(*line as i32) != 0 {line = line.add(1);}
 
-    let (v, mut end) = match *line as u8 {
-        c if is_identifier_start(c as i8) => {
+    let (v, mut end) = match *line {
+        c if is_identifier_start(c) => {
             let start = line;
-            while is_identifier(*line as i8) {line = line.add(1);}
+            while is_identifier(*line) {line = line.add(1);}
             let len = line as isize - start as isize;
 
             let label = arena::sprintf(&mut (*asm).string_arena, c!("%.*s"), len, start);
@@ -557,7 +557,7 @@ pub unsafe fn assemble_statement(out: *mut String_Builder,
     }
 
     for i in 0..len {
-        *name.add(i) = toupper(*name.add(i) as i32) as i8;
+        *name.add(i) = toupper(*name.add(i) as i32) as c_char;
     }
     let instr = match instr_from_string(name) {
         Some(v) => v,