diff --git a/lib/falcon/environment/server.rb b/lib/falcon/environment/server.rb
index ebdc9fb..5d45716 100644
--- a/lib/falcon/environment/server.rb
+++ b/lib/falcon/environment/server.rb
@@ -25,10 +25,10 @@ def authority
 				self.name
 			end
 			
-			# Number of instances to start.
+			# Number of instances to start. By default (when nil), uses `Etc.nprocessors`.
 			# @returns [Integer | nil]
 			def count
-				Etc.nprocessors
+				nil
 			end
 			
 			# Options to use when creating the container.
diff --git a/test/falcon/service/server.rb b/test/falcon/service/server.rb
index 0841fab..21b06af 100644
--- a/test/falcon/service/server.rb
+++ b/test/falcon/service/server.rb
@@ -33,7 +33,7 @@
 		server.setup(container)
 		container.wait_until_ready
 		
-		expect(container.group.running).to have_attributes(size: be > 0)
+		expect(container.group.running).to have_attributes(size: be == Etc.nprocessors)
 		
 		server.stop
 		container.stop