diff --git a/libc3/env.h b/libc3/env.h
index 4b686fd..c9fdb59 100644
--- a/libc3/env.h
+++ b/libc3/env.h
@@ -21,7 +21,7 @@ extern s_env g_c3_env;
void env_clean (s_env *env);
s_env * env_init (s_env *env);
-/* Modifiers */
+/* Modifiers. */
bool env_eval_call (s_env *env, const s_call *call,
s_tag *dest);
bool env_eval_call_arguments (s_env *env, s_list *args,
@@ -59,7 +59,7 @@ bool env_operator_is_unary (s_env *env, const s_ident *op);
s8 env_operator_precedence (s_env *env,
const s_ident *op);
-/* Control structures */
+/* Control structures. */
void env_error_f (s_env *env, const char *fmt, ...);
void env_error_tag (s_env *env, const s_tag *tag);
void env_longjmp (s_env *env, jmp_buf *jmp_buf);