diff --git a/introspection/org.freedesktop.ModemManager1.Modem.xml b/introspection/org.freedesktop.ModemManager1.Modem.xml
index eb9d9050..8ab5ad75 100644
--- a/introspection/org.freedesktop.ModemManager1.Modem.xml
+++ b/introspection/org.freedesktop.ModemManager1.Modem.xml
@@ -148,11 +148,14 @@
 
     <!--
        Command
-       @cmd The command string, e.g. "AT+GCAP" or "+GCAP" (leading AT is inserted if necessary)
-       @timeout The number of seconds to wait for a response
-       @response The modem's response
+       @cmd The command string, e.g. "AT+GCAP" or "+GCAP" (leading AT is inserted if necessary).
+       @timeout The number of seconds to wait for a response.
+       @response The modem's response.
 
        Send an arbitrary AT command to a modem and get the response.
+
+       Note that using this interface call is only allowed when running
+       ModemManager in debug mode.
       -->
     <method name="Command">
       <arg name="cmd"      type="s" direction="in"  />
diff --git a/src/mm-iface-modem.c b/src/mm-iface-modem.c
index 31b575a1..f4b29fef 100644
--- a/src/mm-iface-modem.c
+++ b/src/mm-iface-modem.c
@@ -24,6 +24,7 @@
 #include "mm-sim.h"
 #include "mm-bearer-list.h"
 #include "mm-log.h"
+#include "mm-context.h"
 
 #define SIGNAL_QUALITY_RECENT_TIMEOUT_SEC     60
 #define SIGNAL_QUALITY_CHECK_TIMEOUT_SEC      30
@@ -367,6 +368,17 @@ handle_command_auth_ready (MMBaseModem *self,
         return;
     }
 
+    /* If we are not in Debug mode, report an error */
+    if (!mm_context_get_debug ()) {
+        g_dbus_method_invocation_return_error (ctx->invocation,
+                                               MM_CORE_ERROR,
+                                               MM_CORE_ERROR_UNAUTHORIZED,
+                                               "Cannot send AT command to modem: "
+                                               "operation only allowed in debug mode");
+        handle_command_context_free (ctx);
+        return;
+    }
+
     /* If command is not implemented, report an error */
     if (!MM_IFACE_MODEM_GET_INTERFACE (self)->command ||
         !MM_IFACE_MODEM_GET_INTERFACE (self)->command_finish) {