diff --git a/content/shared/public/nsStyleStruct.h b/content/shared/public/nsStyleStruct.h
index eef469608bf..a5b7e9e7dd6 100644
--- a/content/shared/public/nsStyleStruct.h
+++ b/content/shared/public/nsStyleStruct.h
@@ -188,13 +188,10 @@ struct nsStyleBackground : public nsStyleStruct {
             (NS_STYLE_BG_COLOR_TRANSPARENT | NS_STYLE_BG_IMAGE_NONE);
   }
 
-  PRBool HasFixedBackground() const
-  {
-    // We have to take slower codepaths for fixed background attachment,
-    // but we don't want to do that when there's no image.
-    return mBackgroundAttachment == NS_STYLE_BG_ATTACHMENT_FIXED &&
-           mBackgroundImage;
-  }
+  // We have to take slower codepaths for fixed background attachment,
+  // but we don't want to do that when there's no image.
+  // Not inline because it uses an nsCOMPtr<imgIRequest>
+  PRBool HasFixedBackground() const;
 };
 
 #define BORDER_COLOR_DEFINED      0x80  
diff --git a/content/shared/src/nsStyleStruct.cpp b/content/shared/src/nsStyleStruct.cpp
index eb4e27f48c2..5b2a1210077 100644
--- a/content/shared/src/nsStyleStruct.cpp
+++ b/content/shared/src/nsStyleStruct.cpp
@@ -1088,6 +1088,12 @@ nsChangeHint nsStyleBackground::CalcDifference(const nsStyleBackground& aOther)
   return NS_STYLE_HINT_VISUAL;
 }
 
+PRBool nsStyleBackground::HasFixedBackground() const
+{
+  return mBackgroundAttachment == NS_STYLE_BG_ATTACHMENT_FIXED &&
+         mBackgroundImage;
+}
+
 // --------------------
 // nsStyleDisplay
 //
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index eb4e27f48c2..5b2a1210077 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -1088,6 +1088,12 @@ nsChangeHint nsStyleBackground::CalcDifference(const nsStyleBackground& aOther)
   return NS_STYLE_HINT_VISUAL;
 }
 
+PRBool nsStyleBackground::HasFixedBackground() const
+{
+  return mBackgroundAttachment == NS_STYLE_BG_ATTACHMENT_FIXED &&
+         mBackgroundImage;
+}
+
 // --------------------
 // nsStyleDisplay
 //
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index eef469608bf..a5b7e9e7dd6 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -188,13 +188,10 @@ struct nsStyleBackground : public nsStyleStruct {
             (NS_STYLE_BG_COLOR_TRANSPARENT | NS_STYLE_BG_IMAGE_NONE);
   }
 
-  PRBool HasFixedBackground() const
-  {
-    // We have to take slower codepaths for fixed background attachment,
-    // but we don't want to do that when there's no image.
-    return mBackgroundAttachment == NS_STYLE_BG_ATTACHMENT_FIXED &&
-           mBackgroundImage;
-  }
+  // We have to take slower codepaths for fixed background attachment,
+  // but we don't want to do that when there's no image.
+  // Not inline because it uses an nsCOMPtr<imgIRequest>
+  PRBool HasFixedBackground() const;
 };
 
 #define BORDER_COLOR_DEFINED      0x80