diff --git a/tools/qfcc/include/expr.h b/tools/qfcc/include/expr.h
index dbad3373d..afbc0eaf0 100644
--- a/tools/qfcc/include/expr.h
+++ b/tools/qfcc/include/expr.h
@@ -1004,7 +1004,7 @@ const expr_t *build_for_statement (const expr_t *init, const expr_t *test,
 								   const expr_t *continue_label);
 const expr_t *build_state_expr (const expr_t *e);
 const expr_t *think_expr (struct symbol_s *think_sym);
-int is_lvalue (const expr_t *expr) __attribute__((pure));
+bool is_lvalue (const expr_t *expr) __attribute__((pure));
 const expr_t *assign_expr (const expr_t *dst, const expr_t *src);
 const expr_t *cast_expr (const type_t *t, const expr_t *e);
 const expr_t *cast_error (const expr_t *e, const type_t *t1, const type_t *t2);
diff --git a/tools/qfcc/source/expr_assign.c b/tools/qfcc/source/expr_assign.c
index 4c14707ef..860b9aadf 100644
--- a/tools/qfcc/source/expr_assign.c
+++ b/tools/qfcc/source/expr_assign.c
@@ -81,7 +81,7 @@ check_assign_logic_precedence (const expr_t *dst, const expr_t *src)
 	return 0;
 }
 
-int
+bool
 is_lvalue (const expr_t *expr)
 {
 	switch (expr->type) {
@@ -90,21 +90,21 @@ is_lvalue (const expr_t *expr)
 		case ex_symbol:
 			return expr->symbol->lvalue;
 		case ex_temp:
-			return 1;
+			return true;
 		case ex_expr:
 			if (expr->expr.op == '.') {
-				return 1;
+				return true;
 			}
 			break;
 		case ex_alias:
 			return is_lvalue (expr->alias.expr);
 		case ex_address:
-			return 0;
+			return false;
 		case ex_assign:
-			return 0;
+			return false;
 		case ex_uexpr:
 			if (expr->expr.op == '.') {
-				return 1;
+				return true;
 			}
 			break;
 		case ex_branch:
@@ -138,13 +138,13 @@ is_lvalue (const expr_t *expr)
 			return (is_lvalue (expr->cond.true_expr)
 					&& is_lvalue (expr->cond.false_expr));
 		case ex_field:
-			return 1;
+			return true;
 		case ex_array:
-			return 1;
+			return true;
 		case ex_count:
 			internal_error (expr, "invalid expression");
 	}
-	return 0;
+	return false;
 }
 
 static const expr_t *