diff --git a/engine/src/flutter/libs/minikin/FontCollection.cpp b/engine/src/flutter/libs/minikin/FontCollection.cpp
index cd7b19e009..8919dc1a5e 100644
--- a/engine/src/flutter/libs/minikin/FontCollection.cpp
+++ b/engine/src/flutter/libs/minikin/FontCollection.cpp
@@ -66,7 +66,7 @@ FontCollection::FontCollection(const vector<FontFamily*>& typefaces) :
         mMaxChar = max(mMaxChar, instance->mCoverage->length());
         lastChar.push_back(instance->mCoverage->nextSetBit(0));
     }
-    size_t nPages = mMaxChar >> kLogCharsPerPage;
+    size_t nPages = (mMaxChar + kPageMask) >> kLogCharsPerPage;
     size_t offset = 0;
     for (size_t i = 0; i < nPages; i++) {
         Range dummy;