diff --git a/src/vmrcli.c b/src/vmrcli.c
index 3c29841..c29259f 100644
--- a/src/vmrcli.c
+++ b/src/vmrcli.c
@@ -240,7 +240,10 @@ void parse_command(T_VBVMR_INTERFACE *vmr, char *command)
         get(vmr, command, &res);
         if (res.type == FLOAT_T)
         {
-            set_parameter_float(vmr, command, 1 - res.val.f);
+            if (res.val.f == 1 || res.val.f == 0)
+                set_parameter_float(vmr, command, 1 - res.val.f);
+            else
+                log_warn("%s does not appear to be a boolean parameter", command);
         }
         return;
     }