diff --git a/mozilla/layout/forms/nsFormControlFrame.cpp b/mozilla/layout/forms/nsFormControlFrame.cpp
index 2b748ac4a8c..9617e2aab89 100644
--- a/mozilla/layout/forms/nsFormControlFrame.cpp
+++ b/mozilla/layout/forms/nsFormControlFrame.cpp
@@ -80,15 +80,19 @@ nsFormControlFrame::QueryInterface(const nsIID& aIID, void** aInstancePtr)
 nscoord
 nsFormControlFrame::GetIntrinsicWidth()
 {
-  // Actual width is set in forms.css
-  return 0;
+  // Provide a reasonable default for sites that use an "auto" height.
+  // Note that if you change this, you should change the values in forms.css
+  // as well.  This is the 13px default width minus the 2px default border.
+  return nsPresContext::CSSPixelsToAppUnits(13 - 2 * 2);
 }
 
 nscoord
 nsFormControlFrame::GetIntrinsicHeight()
 {
-  // Actual width is set in forms.css
-  return 0;
+  // Provide a reasonable default for sites that use an "auto" height.
+  // Note that if you change this, you should change the values in forms.css
+  // as well. This is the 13px default width minus the 2px default border.
+  return nsPresContext::CSSPixelsToAppUnits(13 - 2 * 2);
 }
 
 NS_METHOD
diff --git a/mozilla/layout/reftests/bugs/373381-1-ref.html b/mozilla/layout/reftests/bugs/373381-1-ref.html
new file mode 100644
index 00000000000..75b3b5bd876
--- /dev/null
+++ b/mozilla/layout/reftests/bugs/373381-1-ref.html
@@ -0,0 +1,4 @@
+<meta http-equiv="msthemecompatible" content="no">
+<input type="radio">
+<input type="radio">
+<input type="radio">
diff --git a/mozilla/layout/reftests/bugs/373381-1.html b/mozilla/layout/reftests/bugs/373381-1.html
new file mode 100644
index 00000000000..19d4c860cbe
--- /dev/null
+++ b/mozilla/layout/reftests/bugs/373381-1.html
@@ -0,0 +1,4 @@
+<meta http-equiv="msthemecompatible" content="no">
+<input type="radio" style="width: auto">
+<input type="radio" style="height: auto">
+<input type="radio" style="height: auto; width: auto">
diff --git a/mozilla/layout/reftests/bugs/reftest.list b/mozilla/layout/reftests/bugs/reftest.list
index 995dc872be7..8dc3e3b5ec0 100644
--- a/mozilla/layout/reftests/bugs/reftest.list
+++ b/mozilla/layout/reftests/bugs/reftest.list
@@ -190,3 +190,4 @@ fails == 368504-1.html 368504-1-ref.html # bug 368504
 == 371925-1a.html 371925-1-ref.html
 == 371925-1b.html 371925-1-ref.html
 == 372553-1.html 372553-1-ref.html
+== 373381-1.html 373381-1-ref.html