diff --git a/README.md b/README.md
index 4d858ae0..568384af 100644
--- a/README.md
+++ b/README.md
@@ -241,7 +241,7 @@ var defaultOptions = showdown.getDefaultOptions();
     <h3>foo</h3>
     ```
 
- * **parseImgDimensions**: (boolean) [default false] Enable support for setting image dimensions from within markdown syntax.
+ * **parseImgDimensions**: (boolean) [default true] Enable support for setting image dimensions from within markdown syntax.
    Examples:
    ```
    ![foo](foo.jpg =100x80)     simple, assumes units are in px
diff --git a/docs/available-options.md b/docs/available-options.md
index 9cbc3c05..71ced37c 100644
--- a/docs/available-options.md
+++ b/docs/available-options.md
@@ -475,7 +475,7 @@ Open links in new windows.
 Set image dimensions from within Markdown syntax.
 
 * type: `boolean`
-* default value: `false`
+* default value: `true`
 * introduced in: `1.1.0`
 
 === "example"
diff --git a/src/options.js b/src/options.js
index 19deb667..addd830c 100644
--- a/src/options.js
+++ b/src/options.js
@@ -42,7 +42,7 @@ function getDefaultOpts (simple) {
       type: 'integer'
     },
     parseImgDimensions: {
-      defaultValue: false,
+      defaultValue: true,
       describe: 'Turn on/off image dimension parsing',
       type: 'boolean'
     },
diff --git a/src/subParsers/makehtml/images.js b/src/subParsers/makehtml/images.js
index e7fbbc1d..8b28537d 100644
--- a/src/subParsers/makehtml/images.js
+++ b/src/subParsers/makehtml/images.js
@@ -75,7 +75,7 @@ showdown.subParser('makehtml.images', function (text, options, globals) {
       result += ' title="' + title + '"';
     }
 
-    if (width && height) {
+    if (options.parseImgDimensions && width && height) {
       width  = (width === '*') ? 'auto' : width;
       height = (height === '*') ? 'auto' : height;
 
diff --git a/test/functional/makehtml/cases/features/#143.not.support-image-dimensions.html b/test/functional/makehtml/cases/features/#143.not.support-image-dimensions.html
new file mode 100644
index 00000000..0bc6a8a3
--- /dev/null
+++ b/test/functional/makehtml/cases/features/#143.not.support-image-dimensions.html
@@ -0,0 +1,2 @@
+<p><img src="./pic/pic1_50.png" alt="my image" /></p>
+<p><img src="./pic/pic1_50.png" alt="my image2" /></p>
diff --git a/test/functional/makehtml/cases/features/#143.not.support-image-dimensions.md b/test/functional/makehtml/cases/features/#143.not.support-image-dimensions.md
new file mode 100644
index 00000000..ecbd02f5
--- /dev/null
+++ b/test/functional/makehtml/cases/features/#143.not.support-image-dimensions.md
@@ -0,0 +1,5 @@
+![my image](./pic/pic1_50.png =100pxx20px)
+
+![my image2][1]
+
+[1]: ./pic/pic1_50.png =100pxx20px
diff --git a/test/functional/makehtml/testsuite.features.js b/test/functional/makehtml/testsuite.features.js
index 2ef6c38e..62d89bc0 100644
--- a/test/functional/makehtml/testsuite.features.js
+++ b/test/functional/makehtml/testsuite.features.js
@@ -32,6 +32,8 @@ describe('makeHtml() features testsuite', function () {
       var converter;
       if (testsuite[i].name === '#143.support-image-dimensions') {
         converter = new showdown.Converter({parseImgDimensions: true});
+      } else if (testsuite[i].name === '#143.not.support-image-dimensions') {
+        converter = new showdown.Converter({parseImgDimensions: false});
       } else if (testsuite[i].name === '#69.header-level-start') {
         converter = new showdown.Converter({headerLevelStart: 3});
       } else if (testsuite[i].name === '#164.1.simple-autolink' || testsuite[i].name === '#204.certain-links-with-at-and-dot-break-url') {