diff --git a/lib/syntax_tree/node.rb b/lib/syntax_tree/node.rb
index d153ef78..30fd8cf1 100644
--- a/lib/syntax_tree/node.rb
+++ b/lib/syntax_tree/node.rb
@@ -5192,7 +5192,7 @@ def call(q, node)
         else
           # Otherwise, we're going to check the conditional for certain cases.
           case node
-          in predicate: Assign | Command | CommandCall | MAssign | OpAssign
+          in predicate: Assign | Command | CommandCall | MAssign | Not | OpAssign
             false
           in {
                statements: { body: [truthy] },
diff --git a/test/fixtures/if.rb b/test/fixtures/if.rb
index cabea4c3..607af05d 100644
--- a/test/fixtures/if.rb
+++ b/test/fixtures/if.rb
@@ -35,3 +35,9 @@
 %
 if foo {}
 end
+%
+if not a
+  b
+else
+  c
+end