diff --git a/src/core/SkConvolver.cpp b/src/core/SkConvolver.cpp
index 7666e6fadc..e26c8e79e6 100644
--- a/src/core/SkConvolver.cpp
+++ b/src/core/SkConvolver.cpp
@@ -294,8 +294,10 @@ void SkConvolutionFilter1D::AddFilter(int filterOffset,
         filterLength = lastNonZero + 1 - firstNonZero;
         SkASSERT(filterLength > 0);
 
+        // Calling fFilterValues.reset(), or push_back() in a loop, are expensive.
+        fFilterValues.resize_back(filterLength);
         for (int i = firstNonZero; i <= lastNonZero; i++) {
-            fFilterValues.push_back(filterValues[i]);
+            fFilterValues[i - firstNonZero] = filterValues[i];
         }
     } else {
         // Here all the factors were zeroes.