diff --git a/src/core.js b/src/core.js
index ab891487b..677d0b07d 100644
--- a/src/core.js
+++ b/src/core.js
@@ -1483,7 +1483,7 @@ $.extend( $.validator, {
 
 		// https://jqueryvalidation.org/number-method/
 		number: function( value, element ) {
-			return this.optional( element ) || /^(?:-?\d+|-?\d{1,3}(?:,\d{3})+)?(?:\.\d+)?$/.test( value );
+			return this.optional( element ) || /^(?:-?\d+|-?\d{1,3}(?:,\d{3})+)?(?:-?\.\d+)?$/.test( value );
 		},
 
 		// https://jqueryvalidation.org/digits-method/
diff --git a/test/methods.js b/test/methods.js
index a65e4b474..7d58ad7f6 100644
--- a/test/methods.js
+++ b/test/methods.js
@@ -177,6 +177,7 @@ QUnit.test( "number", function( assert ) {
 	assert.ok( method( "123,000.00" ), "Valid decimal" );
 	assert.ok( method( "-123,000.00" ), "Valid decimal" );
 	assert.ok( method( ".100" ), "Valid decimal" );
+	assert.ok( method( "-.100" ), "Valid decimal" );
 	assert.ok( !method( "1230,000.00" ), "Invalid decimal" );
 	assert.ok( !method( "123.0.0,0" ), "Invalid decimal" );
 	assert.ok( !method( "x123" ), "Invalid decimal" );