diff --git a/spec/adapters/signal_adapter/outbound/file_spec.rb b/spec/adapters/signal_adapter/outbound/file_spec.rb
index ea8ea06fa..30a829064 100644
--- a/spec/adapters/signal_adapter/outbound/file_spec.rb
+++ b/spec/adapters/signal_adapter/outbound/file_spec.rb
@@ -24,10 +24,11 @@
       end
 
       describe 'on error' do
-        before(:each) { stub_request(:post, 'http://signal:8080/v2/send').to_return(status: 400) }
+        let(:error_message) { 'User is not registered' }
+        before(:each) { stub_request(:post, 'http://signal:8080/v2/send').to_return(status: 400, body: { error: error_message }.to_json) }
 
         it 'reports the error' do
-          expect(Sentry).to receive(:capture_exception).with(Net::HTTPClientException)
+          expect(Sentry).to receive(:capture_exception).with(SignalAdapter::BadRequestError.new(error_code: 400, message: error_message))
 
           subject.call
         end
diff --git a/spec/adapters/signal_adapter/outbound/text_spec.rb b/spec/adapters/signal_adapter/outbound/text_spec.rb
index 71bb0625b..1654d2566 100644
--- a/spec/adapters/signal_adapter/outbound/text_spec.rb
+++ b/spec/adapters/signal_adapter/outbound/text_spec.rb
@@ -24,10 +24,11 @@
       end
 
       describe 'on error' do
-        before(:each) { stub_request(:post, 'http://signal:8080/v2/send').to_return(status: 400) }
+        let(:error_message) { 'User is not registered' }
+        before(:each) { stub_request(:post, 'http://signal:8080/v2/send').to_return(status: 400, body: { error: error_message }.to_json) }
 
         it 'reports the error' do
-          expect(Sentry).to receive(:capture_exception).with(Net::HTTPClientException)
+          expect(Sentry).to receive(:capture_exception).with(SignalAdapter::BadRequestError.new(error_code: 400, message: error_message))
 
           subject.call
         end