diff --git a/lib/parse_stream/svg.js b/lib/parse_stream/svg.js
index ccb688c..3d91c4a 100644
--- a/lib/parse_stream/svg.js
+++ b/lib/parse_stream/svg.js
@@ -11,7 +11,14 @@ var STATE_IGNORE    = 2; // we got all the data we want, skip the rest
 // max size for pre-svg-tag comments plus svg tag itself
 var MAX_DATA_LENGTH = 65536;
 
-var SVG_HEADER_RE  = /<svg\s[^>]+>/;
+// used to get opening tag for top level element in XML,
+// skipping comments (<!--), directives (<?) and cdata (<![)
+var SVG_HEADER_RE  = /<[-_.:a-zA-Z0-9][^>]*>/;
+
+// test if the top level element is svg + optional namespace,
+// used to skip svg embedded in html
+var SVG_TAG_RE     = /^<([-_.:a-zA-Z0-9]+:)?svg\s/;
+
 var SVG_WIDTH_RE   = /[^-]\bwidth="([^%]+?)"|[^-]\bwidth='([^%]+?)'/;
 var SVG_HEIGHT_RE  = /\bheight="([^%]+?)"|\bheight='([^%]+?)'/;
 var SVG_VIEWBOX_RE = /\bview[bB]ox="(.+?)"|\bview[bB]ox='(.+?)'/;
@@ -48,9 +55,13 @@ function units(str) {
 
 
 function parseSvg(str) {
-  if (!SVG_HEADER_RE.test(str)) return;
+  // get top level element
+  var svgTag = (str.match(SVG_HEADER_RE) || [ '' ])[0];
+
+  // test if top level element is <svg>
+  if (!SVG_TAG_RE.test(svgTag)) return;
 
-  var attrs  = svgAttrs(str.match(SVG_HEADER_RE)[0]);
+  var attrs  = svgAttrs(svgTag);
   var width  = parseFloat(attrs.width);
   var height = parseFloat(attrs.height);
 
diff --git a/lib/parse_sync/svg.js b/lib/parse_sync/svg.js
index a4aee17..3732bb4 100644
--- a/lib/parse_sync/svg.js
+++ b/lib/parse_sync/svg.js
@@ -24,7 +24,14 @@ function canBeSvg(buf) {
 }
 
 
-var SVG_HEADER_RE  = /<svg\s[^>]+>/;
+// used to get opening tag for top level element in XML,
+// skipping comments (<!--), directives (<?) and cdata (<![)
+var SVG_HEADER_RE  = /<[-_.:a-zA-Z0-9][^>]*>/;
+
+// test if the top level element is svg + optional namespace,
+// used to skip svg embedded in html
+var SVG_TAG_RE     = /^<([-_.:a-zA-Z0-9]+:)?svg\s/;
+
 var SVG_WIDTH_RE   = /[^-]\bwidth="([^%]+?)"|[^-]\bwidth='([^%]+?)'/;
 var SVG_HEIGHT_RE  = /\bheight="([^%]+?)"|\bheight='([^%]+?)'/;
 var SVG_VIEWBOX_RE = /\bview[bB]ox="(.+?)"|\bview[bB]ox='(.+?)'/;
@@ -61,9 +68,13 @@ module.exports = function (data) {
     str += String.fromCharCode(data[i]);
   }
 
-  if (!SVG_HEADER_RE.test(str)) return;
+  // get top level element
+  var svgTag = (str.match(SVG_HEADER_RE) || [ '' ])[0];
+
+  // test if top level element is <svg>
+  if (!SVG_TAG_RE.test(svgTag)) return;
 
-  var attrs  = svgAttrs(str.match(SVG_HEADER_RE)[0]);
+  var attrs  = svgAttrs(svgTag);
   var width  = parseFloat(attrs.width);
   var height = parseFloat(attrs.height);
 
diff --git a/test/test_formats.js b/test/test_formats.js
index f2dfdef..362f941 100644
--- a/test/test_formats.js
+++ b/test/test_formats.js
@@ -1256,6 +1256,33 @@ describe('File formats', function () {
       assert.deepStrictEqual(size, { width: 5, height: 4, type: 'svg', mime: 'image/svg+xml', wUnits: 'px', hUnits: 'px' });
     });
 
+    it('should not parse HTML as SVG', async function () {
+      let buf = Buffer.from('<html><body><svg width="5" height="4"></svg></body></html>');
+
+      await assert.rejects(
+        async () => probe(Readable.from([ buf ])),
+        /unrecognized file format/
+      );
+    });
+
+    it('should skip initial comments and directives', async function () {
+      let buf = Buffer.from('<?xml version="1.0"?><!-- comment --><svg width="5" height="4"></svg>');
+
+      assert.deepStrictEqual(
+        await probe(Readable.from([ buf ])),
+        { width: 5, height: 4, type: 'svg', mime: 'image/svg+xml', wUnits: 'px', hUnits: 'px' }
+      );
+    });
+
+    it('should allow SVG namespace', async function () {
+      let buf = Buffer.from('<aaa:svg xmlns:aaa="http://www.w3.org/2000/svg" width="5" height="4"></aaa:svg>');
+
+      assert.deepStrictEqual(
+        await probe(Readable.from([ buf ])),
+        { width: 5, height: 4, type: 'svg', mime: 'image/svg+xml', wUnits: 'px', hUnits: 'px' }
+      );
+    });
+
     it('should skip BOM', async function () {
       let size = await probe(Readable.from([ Buffer.from('\ufeff  <svg width="5" height="4"></svg>') ]));
 
@@ -1349,6 +1376,13 @@ describe('File formats', function () {
           /unrecognized file format/
         );
       });
+
+      it('early termination', async function () {
+        await assert.rejects(
+          async () => probe(Readable.from([ Buffer.from('<svg width="5" height="5"') ])),
+          /unrecognized file format/
+        );
+      });
     });
   });
 
@@ -1385,6 +1419,30 @@ describe('File formats', function () {
       assert.deepStrictEqual(size, { width: 5, height: 4, type: 'svg', mime: 'image/svg+xml', wUnits: 'px', hUnits: 'px' });
     });
 
+    it('should not parse HTML as SVG', async function () {
+      let buf = Buffer.from('<html><body><svg width="5" height="4"></svg></body></html>');
+
+      assert.strictEqual(probe.sync(buf), null);
+    });
+
+    it('should skip initial comments and directives', async function () {
+      let buf = Buffer.from('<?xml version="1.0"?><!-- comment --><svg width="5" height="4"></svg>');
+
+      assert.deepStrictEqual(
+        probe.sync(buf),
+        { width: 5, height: 4, type: 'svg', mime: 'image/svg+xml', wUnits: 'px', hUnits: 'px' }
+      );
+    });
+
+    it('should allow SVG namespace', async function () {
+      let buf = Buffer.from('<aaa:svg xmlns:aaa="http://www.w3.org/2000/svg" width="5" height="4"></aaa:svg>');
+
+      assert.deepStrictEqual(
+        probe.sync(buf),
+        { width: 5, height: 4, type: 'svg', mime: 'image/svg+xml', wUnits: 'px', hUnits: 'px' }
+      );
+    });
+
     it('should skip BOM', async function () {
       let size = probe.sync(Buffer.from('\ufeff  <svg width="5" height="4"></svg>'));
 
@@ -1457,6 +1515,12 @@ describe('File formats', function () {
 
         assert.deepStrictEqual(size, null);
       });
+
+      it('early termination', function () {
+        let size = probe.sync(Buffer.from('<svg width="5" height="5"'));
+
+        assert.deepStrictEqual(size, null);
+      });
     });
   });
 
