diff --git a/ChangeLog b/ChangeLog
index afa212932..37091fb67 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2020-12-26  Werner Lemberg  <wl@gnu.org>
+
+	* src/base/ftobjs.c (pixel_modes): Updated.
+
 2020-12-26  Anuj Verma  <anujv@iitbhilai.ac.in>
 
 	[sdf] Remove custom memory tracker.
diff --git a/include/freetype/ftimage.h b/include/freetype/ftimage.h
index 8cf8a48da..0aee7f07a 100644
--- a/include/freetype/ftimage.h
+++ b/include/freetype/ftimage.h
@@ -209,6 +209,11 @@ FT_BEGIN_HEADER
 #define ft_pixel_mode_pal2   FT_PIXEL_MODE_GRAY2
 #define ft_pixel_mode_pal4   FT_PIXEL_MODE_GRAY4
 
+  /* */
+
+  /* For debugging, the @FT_Pixel_Mode enumeration must stay in sync */
+  /* with the `pixel_modes` array in file `ftobjs.c`.                */
+
 
   /**************************************************************************
    *
diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c
index 45662030c..65c37e1d9 100644
--- a/src/base/ftobjs.c
+++ b/src/base/ftobjs.c
@@ -78,6 +78,9 @@
 #pragma warning( pop )
 #endif
 
+  /* This array must stay in sync with the @FT_Pixel_Mode enumeration */
+  /* (in file `ftimage.h`).                                           */
+
   static const char* const  pixel_modes[] =
   {
     "none",
@@ -85,6 +88,7 @@
     "gray 8-bit bitmap",
     "gray 2-bit bitmap",
     "gray 4-bit bitmap",
+    "SDF 16-bit bitmap",
     "LCD 8-bit bitmap",
     "vertical LCD 8-bit bitmap",
     "BGRA 32-bit color image bitmap"