diff --git a/lib/nostr/event.rb b/lib/nostr/event.rb
index 6f54677..79d1dc8 100644
--- a/lib/nostr/event.rb
+++ b/lib/nostr/event.rb
@@ -203,8 +203,7 @@ module Nostr
     def verify_signature
       crypto = Crypto.new
 
-      return false if id.nil? || pubkey.nil?
-      return false if sig.nil? # FIXME: See https://github.com/soutaro/steep/issues/1079
+      return false if id.nil? || pubkey.nil? || sig.nil?
 
       crypto.valid_sig?(id, pubkey, sig)
     end
diff --git a/nostr.gemspec b/nostr.gemspec
index 337132d..68e6479 100644
--- a/nostr.gemspec
+++ b/nostr.gemspec
@@ -57,7 +57,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rubocop-rspec', '2.29'
   spec.add_development_dependency 'simplecov', '= 0.17'
   spec.add_development_dependency 'simplecov-console', '~> 0.9'
-  spec.add_development_dependency 'steep', '~> 1.6'
+  spec.add_development_dependency 'steep', '~> 1.7.dev3'
   spec.add_development_dependency 'typeprof', '~> 0.21'
   spec.add_development_dependency 'yard', '~> 0.9'
   spec.add_development_dependency 'yard-junk', '~> 0.0.9'