diff --git a/src/gpu/ganesh/text/GrTextBlob.cpp b/src/gpu/ganesh/text/GrTextBlob.cpp
index 138875c518..033967c22a 100644
--- a/src/gpu/ganesh/text/GrTextBlob.cpp
+++ b/src/gpu/ganesh/text/GrTextBlob.cpp
@@ -247,8 +247,11 @@ static bool check_glyph_count(SkReadBuffer& buffer, int glyphCount) {
 
 std::optional<TransformedMaskVertexFiller> TransformedMaskVertexFiller::MakeFromBuffer(
         SkReadBuffer& buffer, GrSubRunAllocator* alloc) {
-    GrMaskFormat maskType = (GrMaskFormat)buffer.readInt();
-    if (!buffer.validate(maskType < kMaskFormatCount)) { return {}; }
+    int checkingMaskType = buffer.readInt();
+    if (!buffer.validate(0 <= checkingMaskType && checkingMaskType < kMaskFormatCount)) {
+        return {};
+    }
+    GrMaskFormat maskType = (GrMaskFormat)checkingMaskType;
     int dstPadding = buffer.readInt();
     if (!buffer.validate(0 <= dstPadding && dstPadding <= 2)) { return {}; }
     SkScalar strikeToSourceScale = buffer.readScalar();