diff --git a/shard.yml b/shard.yml
index 2ab70a9..5e48221 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,11 +1,11 @@
 name: cr-xmpp
-version: 0.1.0
+version: 0.1.1
 description: |
  XMPP/Jabber Library for Crystal focusing on simplicity, simple automation, and IoT.
  
 authors:
   - Ali Naqvi <syed.alinaqvi@gmail.com>
 
-crystal: 0.30.1
+crystal: 0.31.1
 
 license: MIT
diff --git a/src/xmpp/stanza/component.cr b/src/xmpp/stanza/component.cr
index 691a40a..e49d09d 100644
--- a/src/xmpp/stanza/component.cr
+++ b/src/xmpp/stanza/component.cr
@@ -30,7 +30,7 @@ module XMPP::Stanza
       end
     end
 
-    def name
+    def name : String
       "component:handshake"
     end
   end
@@ -73,7 +73,7 @@ module XMPP::Stanza
       end
     end
 
-    def namespace
+    def namespace : String
       xml_name.space
     end
 
diff --git a/src/xmpp/stanza/message/chat_markers.cr b/src/xmpp/stanza/message/chat_markers.cr
index b22f1ec..43c7429 100644
--- a/src/xmpp/stanza/message/chat_markers.cr
+++ b/src/xmpp/stanza/message/chat_markers.cr
@@ -21,7 +21,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
diff --git a/src/xmpp/stanza/message/chat_state.cr b/src/xmpp/stanza/message/chat_state.cr
index 5417f32..5ff0a27 100644
--- a/src/xmpp/stanza/message/chat_state.cr
+++ b/src/xmpp/stanza/message/chat_state.cr
@@ -21,7 +21,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -41,7 +41,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -61,7 +61,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -81,7 +81,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -101,7 +101,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
diff --git a/src/xmpp/stanza/message/hints.cr b/src/xmpp/stanza/message/hints.cr
index 049c0cb..7791066 100644
--- a/src/xmpp/stanza/message/hints.cr
+++ b/src/xmpp/stanza/message/hints.cr
@@ -22,7 +22,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -42,7 +42,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -62,7 +62,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -82,7 +82,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
diff --git a/src/xmpp/stanza/message/receipts.cr b/src/xmpp/stanza/message/receipts.cr
index 31ad7a3..9b79e29 100644
--- a/src/xmpp/stanza/message/receipts.cr
+++ b/src/xmpp/stanza/message/receipts.cr
@@ -23,7 +23,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
@@ -51,7 +51,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, dict)
     end
 
-    def name
+    def name : String
       @@xml_name.local
     end
   end
diff --git a/src/xmpp/stanza/packet.cr b/src/xmpp/stanza/packet.cr
index 6297f56..52b70b1 100644
--- a/src/xmpp/stanza/packet.cr
+++ b/src/xmpp/stanza/packet.cr
@@ -7,9 +7,9 @@ module XMPP::Stanza
 
   module Packet
     abstract def name : String
-    abstract def to_xml(xml : XML::Builder) : String
+    abstract def to_xml(xml : XML::Builder)
 
-    def to_xml
+    def to_xml : String
       val = XML.build(indent: "  ", quote_char: '"') do |xml|
         to_xml xml
       end
diff --git a/src/xmpp/stanza/sasl_auth.cr b/src/xmpp/stanza/sasl_auth.cr
index 82d9c45..7efc74a 100644
--- a/src/xmpp/stanza/sasl_auth.cr
+++ b/src/xmpp/stanza/sasl_auth.cr
@@ -35,7 +35,7 @@ module XMPP::Stanza
       end
     end
 
-    def name
+    def name : String
       "sasl:auth"
     end
   end
@@ -60,7 +60,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space) { elem.text body }
     end
 
-    def name
+    def name : String
       "sasl:success"
     end
   end
@@ -94,7 +94,7 @@ module XMPP::Stanza
       end
     end
 
-    def name
+    def name : String
       "sasl:failure"
     end
   end
@@ -117,7 +117,7 @@ module XMPP::Stanza
       elem.element(@@xml_name.local, xmlns: @@xml_name.space) { elem.text body }
     end
 
-    def name
+    def name : String
       "sasl:challenge"
     end
   end
@@ -143,7 +143,7 @@ module XMPP::Stanza
       end
     end
 
-    def name
+    def name : String
       "sasl:response"
     end
   end