diff --git a/src/booleans.rs b/src/booleans.rs
index 49371de5c..e290b896b 100644
--- a/src/booleans.rs
+++ b/src/booleans.rs
@@ -207,6 +207,10 @@ impl<'a, 'tcx> NonminimalBoolVisitor<'a, 'tcx> {
             let stats = terminal_stats(&expr);
             let mut simplified = expr.simplify();
             for simple in Bool::Not(Box::new(expr.clone())).simplify() {
+                match simple {
+                    Bool::Not(_) | Bool::True | Bool::False => {},
+                    _ => simplified.push(Bool::Not(Box::new(simple.clone()))),
+                }
                 let simple_negated = simple_negate(simple);
                 if simplified.iter().any(|s| *s == simple_negated) {
                     continue;
diff --git a/tests/compile-fail/booleans.rs b/tests/compile-fail/booleans.rs
index 31c160980..4630a4635 100644
--- a/tests/compile-fail/booleans.rs
+++ b/tests/compile-fail/booleans.rs
@@ -6,14 +6,13 @@
 fn main() {
     let a: bool = unimplemented!();
     let b: bool = unimplemented!();
+    let c: bool = unimplemented!();
     let _ = a && b || a; //~ ERROR this boolean expression contains a logic bug
     //|~ HELP for further information visit
     //|~ HELP this expression can be optimized out
     //|~ HELP it would look like the following
     //|~ SUGGESTION let _ = a;
-    let _ = !(a && b); //~ ERROR this boolean expression can be simplified
-    //|~ HELP for further information visit
-    //|~ SUGGESTION let _ = !b || !a;
+    let _ = !(a && b);
     let _ = !true; //~ ERROR this boolean expression can be simplified
     //|~ HELP for further information visit
     //|~ SUGGESTION let _ = false;
@@ -36,4 +35,6 @@ fn main() {
 
     // don't lint on cfgs
     let _ = cfg!(you_shall_not_not_pass) && a;
+
+    let _ = !(a && b || c);
 }