diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index e09e542..c7e310e 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -693,7 +693,9 @@
             const uint8_t*  src = (const uint8_t*)fFace->glyph->bitmap.buffer;
             uint8_t*        dst = (uint8_t*)glyph.fImage;
 
-            if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_GRAY) {
+            if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_GRAY ||
+                (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO &&
+                 glyph.fMaskFormat == SkMask::kBW_Format)) {
                 unsigned    srcRowBytes = fFace->glyph->bitmap.pitch;
                 unsigned    dstRowBytes = glyph.rowBytes();
                 unsigned    minRowBytes = SkMin32(srcRowBytes, dstRowBytes);
@@ -705,7 +707,8 @@
                     src += srcRowBytes;
                     dst += dstRowBytes;
                 }
-            } else if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO) {
+            } else if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO &&
+                       glyph.fMaskFormat == SkMask::kA8_Format) {
                 for (int y = 0; y < fFace->glyph->bitmap.rows; ++y) {
                     uint8_t byte = 0;
                     int bits = 0;
@@ -726,6 +729,8 @@
                     src += fFace->glyph->bitmap.pitch;
                     dst += glyph.rowBytes();
                 }
+            } else {
+              SkASSERT(!"unknown glyph bitmap transform needed");
             }
 
             if (lcdRenderMode)