diff --git a/.github/workflows/autotest.yml b/.github/workflows/autotest.yml
index a0eded17..4e4c5836 100644
--- a/.github/workflows/autotest.yml
+++ b/.github/workflows/autotest.yml
@@ -8,7 +8,8 @@ on:
 
 jobs:
   mac:
-    runs-on: macos-latest
+    # the macos-latest may randomly give us macos-12.6.9 or macos-12.7.0 which may break the autotest.
+    runs-on: macos-13
     steps:
       - name: Check Out Repo
         uses: actions/checkout@v3
diff --git a/test/baseline/version.json b/test/baseline/version.json
index f04cb027..fb7605cf 100644
--- a/test/baseline/version.json
+++ b/test/baseline/version.json
@@ -53,7 +53,7 @@
         "PixelMap_RGBA_to_RGBA_100_-100": "d010fb8",
         "PixelMap_RGBA_to_RGBA_100_100": "d010fb8",
         "PixelMap_RGBA_to_RGBA_1010102": "d010fb8",
-        "PixelMap_RGBA_to_RGBA_F16": "c433c89",
+        "PixelMap_RGBA_to_RGBA_F16": "926727c",
         "PixelMap_RGBA_to_bgr_A": "d010fb8",
         "PixelMap_RGBA_to_rgb_A": "d010fb8",
         "PixelMap_alpha_to_BGRA": "d010fb8",
diff --git a/test/src/ReadPixelsTest.cpp b/test/src/ReadPixelsTest.cpp
index 78664008..456ea2cd 100644
--- a/test/src/ReadPixelsTest.cpp
+++ b/test/src/ReadPixelsTest.cpp
@@ -41,7 +41,7 @@ TGFX_TEST(ReadPixelsTest, PixelMap) {
   auto RGBAInfo = ImageInfo::Make(width, height, ColorType::RGBA_8888, AlphaType::Unpremultiplied);
   auto byteSize = RGBAInfo.byteSize();
   Buffer pixelsA(byteSize);
-  Buffer pixelsB(byteSize * 3);
+  Buffer pixelsB(byteSize * 2);
   auto result = codec->readPixels(RGBAInfo, pixelsA.data());
   EXPECT_TRUE(result);
 
@@ -65,10 +65,7 @@ TGFX_TEST(ReadPixelsTest, PixelMap) {
   CHECK_PIXELS(Gray8Info, pixelsB.data(), "PixelMap_RGBA_to_Gray8");
 
   pixelsB.clear();
-  // Set the rowByte != width * 8 to force the RGBA_F16 PixelMap converted to RGBA_8888 when doing
-  // baseline comparing. Otherwise, the RGBA_F16 data may have floating error when compared.
-  auto f16RowBytes = (width + 1) * 8;
-  auto RGBAF16Info = RGBAInfo.makeColorType(ColorType::RGBA_F16, f16RowBytes);
+  auto RGBAF16Info = RGBAInfo.makeColorType(ColorType::RGBA_F16);
   result = RGBAMap.readPixels(RGBAF16Info, pixelsB.data());
   ASSERT_TRUE(result);
   CHECK_PIXELS(RGBAF16Info, pixelsB.data(), "PixelMap_RGBA_to_RGBA_F16");