diff --git a/.gitignore b/.gitignore
index 41e5a9d..4a5f0fc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 **/*.o
 **/*~
 lc
+*.swp
diff --git a/lc.c b/lc.c
index 529abad..7125d91 100644
--- a/lc.c
+++ b/lc.c
@@ -168,7 +168,13 @@ void print_ast(ast_node *node, int depth) {
 			print_ast(node->expr.var_decl.value, depth + 1);
 			break;
 		case NODE_FUNCTION:
-			printf("FunctionDef (Fields missing in struct)\n");
+			printf("Function: %.*s\n", (int)node->expr.function.name_len, node->expr.function.name);
+			m = node->expr.function.parameters;
+			while (m) {
+				print_ast(m->type, depth + 1);
+				m = m->next;
+			}
+			print_ast(node->expr.function.body, depth + 1);
 			break;
 		case NODE_RETURN:
 			printf("Return:\n");
@@ -203,7 +209,7 @@ void print_ast(ast_node *node, int depth) {
 
 int main(void)
 {
-	FILE *fp = fopen("test.c", "r");
+	FILE *fp = fopen("test.l", "r");
 	usize size = 0;
 	fseek(fp, 0, SEEK_END);
 	size = ftell(fp);
diff --git a/parser.c b/parser.c
index 8aba74f..e501ab7 100644
--- a/parser.c
+++ b/parser.c
@@ -869,6 +869,60 @@ static ast_node *parse_struct(parser *p)
 	return structure;
 }
 
+static ast_node *parse_function(parser *p)
+{
+	ast_node *fn = arena_alloc(p->allocator, sizeof(ast_node));
+	fn->type = NODE_FUNCTION;
+	fn->expr.function.type = peek(p)->lexeme;
+	fn->expr.function.type_len = peek(p)->lexeme_len;
+	advance(p);
+	fn->expr.function.name = peek(p)->lexeme;
+	fn->expr.function.name_len = peek(p)->lexeme_len;
+	advance(p);
+	/* Consume `(` */
+	advance(p);
+
+	if (match(p, TOKEN_RPAREN)) {
+		fn->expr.function.body = parse_compound(p);
+		fn->expr.function.parameters = NULL;
+		fn->expr.function.parameters_len = 0;
+		return fn;
+	}
+	member *prev = parse_member(p);
+	member *head = prev;
+	fn->expr.function.parameters = head;
+	fn->expr.function.parameters_len = 1;
+	if (!match(p, TOKEN_COMMA)) {
+		if (!match(p, TOKEN_RPAREN)) {
+			error(p, "expected `,`.");
+			return NULL;
+		} else {
+			fn->expr.function.body = parse_compound(p);
+			return fn;
+		}
+	}
+	while (!match(p, TOKEN_RPAREN)) {
+		member *current = parse_member(p);
+		if (!current) {
+			error(p, "expected parameter.");
+			return NULL;
+		}
+		prev->next = current;
+		if (!match(p, TOKEN_COMMA)) {
+			if (!match_peek(p, TOKEN_RPAREN)) {
+				error(p, "expected `,`.");
+				return NULL;
+			}
+		}
+		fn->expr.function.parameters_len += 1;
+
+		prev = current;
+	}
+	fn->expr.function.body = parse_compound(p);
+
+	return fn;
+}
+
 static ast_node *parse_statement(parser *p)
 {
 	if (match(p, TOKEN_BREAK))
@@ -993,6 +1047,10 @@ static ast_node *parse_statement(parser *p)
 	}
 	else if (match_peek(p, TOKEN_IDENTIFIER) && p->tokens->next && p->tokens->next->type == TOKEN_IDENTIFIER)
 	{
+		if (p->tokens->next->next && p->tokens->next->next->type == TOKEN_LPAREN) {
+			/* Function definition. */
+			return parse_function(p);
+		}
 		/* Variable declaration. */
 		ast_node *node = arena_alloc(p->allocator, sizeof(ast_node));
 		node->type = NODE_VAR_DECL;
diff --git a/parser.h b/parser.h
index 837bf70..2b201e0 100644
--- a/parser.h
+++ b/parser.h
@@ -191,6 +191,15 @@ typedef struct _ast_node {
 			char *name;
 			usize name_len;
 		} structure;
+		struct {
+			member *parameters;
+			usize parameters_len;
+			char *name;
+			usize name_len;
+			char *type;
+			usize type_len;
+			struct _ast_node *body;
+		} function;
 		struct {
 			variant *variants;
 			char *name;
diff --git a/test.c b/test.c
deleted file mode 100644
index 99ec2a1..0000000
--- a/test.c
+++ /dev/null
@@ -1,7 +0,0 @@
-enum {
-	a = 4,
-	b,
-	c
-}
-
-a = 3;
diff --git a/test.l b/test.l
new file mode 100644
index 0000000..6f87c31
--- /dev/null
+++ b/test.l
@@ -0,0 +1,4 @@
+u32 a(u32 a)
+{
+	u32 x = 3;
+}