diff --git a/README.md b/README.md
index 9600d9b..9fc22aa 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ Usage: fakehttp [options]
 
 Options:
   -h <hostname>      hostname for obfuscation (required)
-  -i <interface>     either interface name (required)
+  -i <interface>     network interface name (required)
   -m <mark>          fwmark for bypassing the queue
   -n <number>        netfilter queue number
   -r <repeat>        duplicate generated packets for <repeat> times
diff --git a/src/fakehttp.c b/src/fakehttp.c
index 9d4bb8e..c751c8e 100644
--- a/src/fakehttp.c
+++ b/src/fakehttp.c
@@ -61,7 +61,7 @@ static void print_usage(const char *name)
             "\n"
             "Options:\n"
             "  -h <hostname>      hostname for obfuscation (required)\n"
-            "  -i <interface>     either interface name (required)\n"
+            "  -i <interface>     network interface name (required)\n"
             "  -m <mark>          fwmark for bypassing the queue\n"
             "  -n <number>        netfilter queue number\n"
             "  -r <repeat>        duplicate generated packets for <repeat> "