diff --git a/tests/lhs-test.html b/tests/lhs-test.html
index cc53a3845..1f2a7736b 100644
--- a/tests/lhs-test.html
+++ b/tests/lhs-test.html
@@ -8,7 +8,7 @@ B
   <title></title>
   <style type="text/css">code{white-space: pre;}</style>
   <style type="text/css">
-div.sourceCode { x-overflow: auto; }
+div.sourceCode { overflow-x: auto; }
 table.sourceCode, tr.sourceCode, td.lineNumbers, td.sourceCode {
   margin: 0; padding: 0; vertical-align: baseline; border: none; }
 table.sourceCode { width: 100%; line-height: 100%; }
diff --git a/tests/lhs-test.html+lhs b/tests/lhs-test.html+lhs
index 8fbb16e10..492d9c718 100644
--- a/tests/lhs-test.html+lhs
+++ b/tests/lhs-test.html+lhs
@@ -7,7 +7,7 @@
   <title></title>
   <style type="text/css">code{white-space: pre;}</style>
   <style type="text/css">
-div.sourceCode { x-overflow: auto; }
+div.sourceCode { overflow-x: auto; }
 table.sourceCode, tr.sourceCode, td.lineNumbers, td.sourceCode {
   margin: 0; padding: 0; vertical-align: baseline; border: none; }
 table.sourceCode { width: 100%; line-height: 100%; }