diff --git a/proxy_server.rb b/proxy_server.rb
index 4df415b..1ca8b20 100644
--- a/proxy_server.rb
+++ b/proxy_server.rb
@@ -31,6 +31,10 @@ class ProxyServer < Sinatra::Base
     halt 401, {error: "Token has #{error.to_s.downcase}"}.to_json
   end
 
+  error do |error|
+    halt 502, {error: error.message}.to_json
+  end
+
   # Handle CORS headers
   before do
     headers "Access-Control-Allow-Origin" => "*",
diff --git a/spec/proxy_server_spec.rb b/spec/proxy_server_spec.rb
index 23a3cd4..efeb289 100644
--- a/spec/proxy_server_spec.rb
+++ b/spec/proxy_server_spec.rb
@@ -13,7 +13,7 @@
   include Rack::Test::Methods
 
   def app
-    ProxyServer
+    @app ||= ProxyServer
   end
 
   def expect_header(k, v)
@@ -187,6 +187,28 @@ def expect_json_body(k, v)
           expect_header("access-control-allow-origin", "*")
         end
       end
+
+      context "when target request returns an error" do
+        before(:each) do
+          # This sinatra config setting simulates the production
+          # behavior (because in dev/test the generic error handler is
+          # not called, instead errors are raised for real)
+          @app = Sinatra.new(ProxyServer) do
+            set :raise_errors, false
+          end
+          stub_request(:get, "https://jsonplaceholder.typicode.com/posts")
+            .to_raise(OpenSSL::SSL::SSLError)
+          header "x-bump-proxy-token", proxy_token
+          header "Content-Type", "application/json"
+          get "/#{target_url}"
+        end
+
+        it "returns a 502 and forwards the error message" do
+          expect(last_response.status).to eq(502)
+          response_body = JSON.parse(last_response.body)
+          expect(response_body["error"]).to eq("Exception from WebMock")
+        end
+      end
     end
 
     context "but is invalid" do