diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index 27f3e6f5f5..f4a0b82753 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -6427,6 +6427,15 @@ nsRuleNode::ComputeDisplayData(void* aStartStruct,
       display->mOverflowY = NS_STYLE_OVERFLOW_HIDDEN;
     }
 
+    // If 'visible' is specified but doesn't match the other dimension, it
+    // turns into 'auto'.
+    if (display->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE) {
+      display->mOverflowX = NS_STYLE_OVERFLOW_AUTO;
+    }
+    if (display->mOverflowY == NS_STYLE_OVERFLOW_VISIBLE) {
+      display->mOverflowY = NS_STYLE_OVERFLOW_AUTO;
+    }
+    
   }
 
   // When 'contain: paint', update overflow from 'visible' to 'clip'.