diff --git a/adb/commandline.cpp b/adb/commandline.cpp
index 37d114605..ff4eb2200 100644
--- a/adb/commandline.cpp
+++ b/adb/commandline.cpp
@@ -157,7 +157,7 @@ static void help() {
         "                                 (-r: replace existing application)\n"
         "                                 (-t: allow test packages)\n"
         "                                 (-s: install application on sdcard)\n"
-        "                                 (-d: allow version code downgrade)\n"
+        "                                 (-d: allow version code downgrade (debuggable packages only))\n"
         "                                 (-g: grant all runtime permissions)\n"
         "  adb install-multiple [-lrtsdpg] <file...>\n"
         "                               - push this package file to the device and install it\n"
@@ -165,7 +165,7 @@ static void help() {
         "                                 (-r: replace existing application)\n"
         "                                 (-t: allow test packages)\n"
         "                                 (-s: install application on sdcard)\n"
-        "                                 (-d: allow version code downgrade)\n"
+        "                                 (-d: allow version code downgrade (debuggable packages only))\n"
         "                                 (-p: partial application install)\n"
         "                                 (-g: grant all runtime permissions)\n"
         "  adb uninstall [-k] <package> - remove this app package from the device\n"