diff --git a/layout/generic/nsBlockBandData.cpp b/layout/generic/nsBlockBandData.cpp
index ef56e9c8666c..98ebdb7aebe6 100644
--- a/layout/generic/nsBlockBandData.cpp
+++ b/layout/generic/nsBlockBandData.cpp
@@ -145,6 +145,8 @@ nsBlockBandData::ComputeAvailSpaceRect()
     mAvailSpace.y = 0;
     mAvailSpace.width = 0;
     mAvailSpace.height = 0;
+    mLeftFloaters = 0;
+    mRightFloaters = 0;
     return;
   }
 
diff --git a/layout/html/base/src/nsBlockBandData.cpp b/layout/html/base/src/nsBlockBandData.cpp
index ef56e9c8666c..98ebdb7aebe6 100644
--- a/layout/html/base/src/nsBlockBandData.cpp
+++ b/layout/html/base/src/nsBlockBandData.cpp
@@ -145,6 +145,8 @@ nsBlockBandData::ComputeAvailSpaceRect()
     mAvailSpace.y = 0;
     mAvailSpace.width = 0;
     mAvailSpace.height = 0;
+    mLeftFloaters = 0;
+    mRightFloaters = 0;
     return;
   }