diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..62d1a98
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,33 @@
+name: C-lang CI
+
+on:
+  push:
+    branches: ["master"]
+  pull_request:
+    branches: ["master"]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: gcc
+        run: mkdir -p build && gcc -v -Wall -Wextra -Werror src/*.c src/*.h -lm -o build/out
+
+  build-release:
+    needs: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: aclocal
+        run: aclocal
+      - name: autoconf
+        run: autoconf
+      - name: automake
+        run: automake --add-missing
+      - name: configure
+        run: ./configure
+      - name: make
+        run: make
+      - name: make distcheck
+        run: make distcheck
diff --git a/Makefile.dev b/Makefile.dev
index 0ef8818..023a720 100644
--- a/Makefile.dev
+++ b/Makefile.dev
@@ -9,7 +9,7 @@ clean:
 
 build:
 	@mkdir -p build
-	gcc -Wall src/*.c src/*.h -lm -o build/$(TARGET)
+	gcc -v -Wall -Wextra src/*.c src/*.h -lm -o build/$(TARGET)
 
 .PHONY: install
 install: build
diff --git a/src/args.c b/src/args.c
index f6885e4..c335efd 100644
--- a/src/args.c
+++ b/src/args.c
@@ -68,7 +68,7 @@ bool is_number(char *value) {
     return false;
   }
   unsigned long value_len = strlen(value);
-  int i;
+  unsigned int i;
   for (i = 0; i < value_len; i++) {
     if (!is_digit(value[i])) {
       return false;