diff --git a/lib/geoip.js b/lib/geoip.js
index 7b6f1cc1..04732abe 100644
--- a/lib/geoip.js
+++ b/lib/geoip.js
@@ -202,6 +202,18 @@ function lookup6(ip) {
 	} while(1);
 }
 
+function get4mapped(ip) {
+    var ipv6 = ip.toUpperCase();
+    var v6prefixes = ['0:0:0:0:0:FFFF:', '::FFFF:'];
+    for (var i = 0; i < v6prefixes.length; i++) {
+        var v6prefix = v6prefixes[i];
+        if (ipv6.indexOf(v6prefix) == 0) {
+            return ipv6.substring(v6prefix.length);
+        }
+    }
+    return null;
+}
+
 function preload(callback) {
 	var datFile;
 	var datSize;
@@ -449,7 +461,12 @@ module.exports = {
 		} else if (net.isIP(ip) === 4) {
 			return lookup4(utils.aton4(ip));
 		} else if (net.isIP(ip) === 6) {
-			return lookup6(utils.aton6(ip));
+			var ipv4 = get4mapped(ip);
+			if (ipv4) {
+				return lookup4(utils.aton4(ipv4));
+			} else {
+				return lookup6(utils.aton6(ip));
+			}
 		}
 
 		return null;
diff --git a/test/tests.js b/test/tests.js
index ed6bf6e0..84d1ba3f 100644
--- a/test/tests.js
+++ b/test/tests.js
@@ -39,6 +39,17 @@ module.exports = {
 		test.equal(actual.city, "Santa Ana");
 		test.equal(actual.metro, 803);
 
+		test.done();
+	},
+
+	testIPv4MappedIPv6: function (test) {
+		test.expect(2);
+
+		var actual = geoip.lookup("::ffff:173.185.182.82");
+
+		test.equal(actual.city, "Glen Rose");
+		test.equal(actual.metro, 623);
+
 		test.done();
 	}
 };