diff --git a/bpf/headers/include/bpf_helpers.h b/bpf/headers/include/bpf_helpers.h
index 782f995..1a9fd31 100644
--- a/bpf/headers/include/bpf_helpers.h
+++ b/bpf/headers/include/bpf_helpers.h
@@ -392,6 +392,7 @@
 static long (*bpf_get_stackid)(void* ctx, void* map, uint64_t flags) = (void*) BPF_FUNC_get_stackid;
 static long (*bpf_get_current_comm)(void* buf, uint32_t buf_size) = (void*) BPF_FUNC_get_current_comm;
 
+// GPL only:
 static int (*bpf_trace_printk)(const char* fmt, int fmt_size, ...) = (void*) BPF_FUNC_trace_printk;
 #define bpf_printf(s, n...) bpf_trace_printk(s, sizeof(s), ## n)
 // Note: bpf only supports up to 3 arguments, log via: bpf_printf("msg %d %d %d", 1, 2, 3);