diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 71a85d4c..98dd3d6d 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -15,7 +15,10 @@
   </component>
   <component name="ChangeListManager">
     <list default="true" id="9b41f7a2-a71e-4923-91fb-249d7815b3e7" name="Default" comment="">
-      <change beforePath="$PROJECT_DIR$/README.md" beforeDir="false" afterPath="$PROJECT_DIR$/README.md" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/CHANGELOG.md" beforeDir="false" afterPath="$PROJECT_DIR$/CHANGELOG.md" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/lib/flutter_inappbrowser.dart" beforeDir="false" afterPath="$PROJECT_DIR$/lib/flutter_inappbrowser.dart" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/pubspec.yaml" beforeDir="false" afterPath="$PROJECT_DIR$/pubspec.yaml" afterDir="false" />
     </list>
     <ignored path="$PROJECT_DIR$/.dart_tool/" />
     <ignored path="$PROJECT_DIR$/.idea/" />
@@ -35,8 +38,8 @@
       <file leaf-file-name="flutter_inappbrowser.dart" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/lib/flutter_inappbrowser.dart">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="-17952">
-              <caret line="256" column="65" selection-start-line="256" selection-start-column="5" selection-end-line="256" selection-end-column="65" />
+            <state relative-caret-position="3075">
+              <caret line="722" column="20" lean-forward="true" selection-start-line="722" selection-start-column="20" selection-end-line="722" selection-end-column="20" />
               <folding>
                 <element signature="e#814#831#0" expanded="true" />
               </folding>
@@ -47,8 +50,8 @@
       <file leaf-file-name="main.dart" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/example/lib/main.dart">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="90">
-              <caret line="6" selection-start-line="6" selection-end-line="9" selection-end-column="3" />
+            <state relative-caret-position="300">
+              <caret line="20" column="39" lean-forward="true" selection-start-line="20" selection-start-column="39" selection-end-line="20" selection-end-column="39" />
               <folding>
                 <element signature="e#0#20#0" expanded="true" />
               </folding>
@@ -56,7 +59,7 @@
           </provider>
         </entry>
       </file>
-      <file leaf-file-name="README.md" pinned="false" current-in-tab="true">
+      <file leaf-file-name="README.md" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/README.md">
           <provider selected="true" editor-type-id="text-editor">
             <state relative-caret-position="327">
@@ -68,11 +71,20 @@
           </provider>
         </entry>
       </file>
-      <file leaf-file-name="CHANGELOG.md" pinned="false" current-in-tab="false">
+      <file leaf-file-name="CHANGELOG.md" pinned="false" current-in-tab="true">
         <entry file="file://$PROJECT_DIR$/CHANGELOG.md">
           <provider selected="true" editor-type-id="text-editor">
-            <state>
-              <caret selection-end-line="9" selection-end-column="60" />
+            <state relative-caret-position="45">
+              <caret line="3" column="21" lean-forward="true" selection-start-line="3" selection-start-column="21" selection-end-line="3" selection-end-column="21" />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file leaf-file-name="pubspec.yaml" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/pubspec.yaml">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="15">
+              <caret line="1" column="103" selection-start-line="1" selection-start-column="103" selection-end-line="1" selection-end-column="103" />
             </state>
           </provider>
         </entry>
@@ -159,11 +171,11 @@
         <option value="$PROJECT_DIR$/example/assets/index.html" />
         <option value="$PROJECT_DIR$/example/ios/Flutter/Generated.xcconfig" />
         <option value="$PROJECT_DIR$/example/pubspec.yaml" />
+        <option value="$PROJECT_DIR$/README.md" />
         <option value="$PROJECT_DIR$/pubspec.yaml" />
-        <option value="$PROJECT_DIR$/CHANGELOG.md" />
         <option value="$PROJECT_DIR$/lib/flutter_inappbrowser.dart" />
         <option value="$PROJECT_DIR$/example/lib/main.dart" />
-        <option value="$PROJECT_DIR$/README.md" />
+        <option value="$PROJECT_DIR$/CHANGELOG.md" />
       </list>
     </option>
   </component>
@@ -647,40 +659,16 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/pubspec.yaml">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="30">
-          <caret line="2" column="14" selection-start-line="2" selection-start-column="14" selection-end-line="2" selection-end-column="14" />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/lib/flutter_inappbrowser.dart">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="-17952">
-          <caret line="256" column="65" selection-start-line="256" selection-start-column="5" selection-end-line="256" selection-end-column="65" />
+        <state relative-caret-position="3075">
+          <caret line="722" column="20" lean-forward="true" selection-start-line="722" selection-start-column="20" selection-end-line="722" selection-end-column="20" />
           <folding>
             <element signature="e#814#831#0" expanded="true" />
           </folding>
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/CHANGELOG.md">
-      <provider selected="true" editor-type-id="text-editor">
-        <state>
-          <caret selection-end-line="9" selection-end-column="60" />
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/example/lib/main.dart">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="90">
-          <caret line="6" selection-start-line="6" selection-end-line="9" selection-end-column="3" />
-          <folding>
-            <element signature="e#0#20#0" expanded="true" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/README.md">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="327">
@@ -691,6 +679,30 @@
         </state>
       </provider>
     </entry>
+    <entry file="file://$PROJECT_DIR$/example/lib/main.dart">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="300">
+          <caret line="20" column="39" lean-forward="true" selection-start-line="20" selection-start-column="39" selection-end-line="20" selection-end-column="39" />
+          <folding>
+            <element signature="e#0#20#0" expanded="true" />
+          </folding>
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/pubspec.yaml">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="15">
+          <caret line="1" column="103" selection-start-line="1" selection-start-column="103" selection-end-line="1" selection-end-column="103" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/CHANGELOG.md">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="45">
+          <caret line="3" column="21" lean-forward="true" selection-start-line="3" selection-start-column="21" selection-end-line="3" selection-end-column="21" />
+        </state>
+      </provider>
+    </entry>
   </component>
   <component name="masterDetails">
     <states>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index db02cffc..922ca138 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.5.51
+
+- updated `pubspec.yaml`
+- updated `README.md`
+
 ## 0.5.5
 
 - added `getUrl` method for the `InAppWebViewController` class
diff --git a/lib/flutter_inappbrowser.dart b/lib/flutter_inappbrowser.dart
index 11011279..12481bc9 100644
--- a/lib/flutter_inappbrowser.dart
+++ b/lib/flutter_inappbrowser.dart
@@ -524,15 +524,15 @@ class ChromeSafariBrowser {
   }
 }
 
-typedef void onWebViewCreatedCallback(InAppWebViewController controller);
-typedef void onWebViewLoadStartCallback(InAppWebViewController controller, String url);
-typedef void onWebViewLoadStopCallback(InAppWebViewController controller, String url);
-typedef void onWebViewLoadErrorCallback(InAppWebViewController controller, String url, int code, String message);
-typedef void onWebViewProgressChangedCallback(InAppWebViewController controller, int progress);
-typedef void onWebViewConsoleMessageCallback(InAppWebViewController controller, ConsoleMessage consoleMessage);
-typedef void shouldOverrideUrlLoadingCallback(InAppWebViewController controller, String url);
-typedef void onWebViewLoadResourceCallback(InAppWebViewController controller, WebResourceResponse response, WebResourceRequest request);
-typedef void onWebViewScrollChangedCallback(InAppWebViewController controller, int x, int y);
+typedef onWebViewCreatedCallback = void Function(InAppWebViewController controller);
+typedef onWebViewLoadStartCallback = void Function(InAppWebViewController controller, String url);
+typedef onWebViewLoadStopCallback = void Function(InAppWebViewController controller, String url);
+typedef onWebViewLoadErrorCallback = void Function(InAppWebViewController controller, String url, int code, String message);
+typedef onWebViewProgressChangedCallback = void Function(InAppWebViewController controller, int progress);
+typedef onWebViewConsoleMessageCallback = void Function(InAppWebViewController controller, ConsoleMessage consoleMessage);
+typedef shouldOverrideUrlLoadingCallback = void Function(InAppWebViewController controller, String url);
+typedef onWebViewLoadResourceCallback = void Function(InAppWebViewController controller, WebResourceResponse response, WebResourceRequest request);
+typedef onWebViewScrollChangedCallback = void Function(InAppWebViewController controller, int x, int y);
 
 ///Initial [data] as a content for an [InAppWebView] instance, using [baseUrl] as the base URL for it.
 ///The [mimeType] property specifies the format of the data.
diff --git a/pubspec.yaml b/pubspec.yaml
index 46eebaa6..8dc7b493 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: flutter_inappbrowser
-description: A Flutter plugin that allows you to add an inline webview or open an in-app browser window. (inspired by the popular cordova-plugin-inappbrowser).
-version: 0.5.5
+description: A Flutter plugin that allows you to add an inline webview or open an in-app browser window (inspired by the popular cordova-plugin-inappbrowser).
+version: 0.5.51
 author: Lorenzo Pichilli <pichillilorenzo@gmail.com>
 homepage: https://github.com/pichillilorenzo/flutter_inappbrowser
 
 environment:
-  sdk: ">=2.1.0-dev.7.1 <3.0.0"
+  sdk: ">=2.0.0-dev <3.0.0"
   flutter: ">=0.10.1 <2.0.0"
 
 dependencies: