diff --git a/content/shared/public/nsStyleStruct.h b/content/shared/public/nsStyleStruct.h
index 34abbf57f14f..f2b414e1f14d 100644
--- a/content/shared/public/nsStyleStruct.h
+++ b/content/shared/public/nsStyleStruct.h
@@ -659,7 +659,8 @@ struct nsStyleText : public nsStyleStruct {
   nsStyleCoord  mWordSpacing;           // [inherited] 
   
   PRBool WhiteSpaceIsSignificant() const {
-    return mWhiteSpace == NS_STYLE_WHITESPACE_PRE;
+    return mWhiteSpace == NS_STYLE_WHITESPACE_PRE ||
+           mWhiteSpace == NS_STYLE_WHITESPACE_MOZ_PRE_WRAP;
   }
 };
 
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index 34abbf57f14f..f2b414e1f14d 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -659,7 +659,8 @@ struct nsStyleText : public nsStyleStruct {
   nsStyleCoord  mWordSpacing;           // [inherited] 
   
   PRBool WhiteSpaceIsSignificant() const {
-    return mWhiteSpace == NS_STYLE_WHITESPACE_PRE;
+    return mWhiteSpace == NS_STYLE_WHITESPACE_PRE ||
+           mWhiteSpace == NS_STYLE_WHITESPACE_MOZ_PRE_WRAP;
   }
 };