diff --git a/coders/json.c b/coders/json.c
index d81a7d1..37b919d 100644
--- a/coders/json.c
+++ b/coders/json.c
@@ -618,7 +618,7 @@
       if (channel_statistics == (ChannelStatistics *) NULL)
         return(MagickFalse);
       colorspace=image->colorspace;
-      if (IsImageGray(image,exception) != MagickFalse)
+      if (SetImageGray(image,exception) != MagickFalse)
         colorspace=GRAYColorspace;
       (void) FormatLocaleFile(file,"Channel %s locations:\n",locate);
       switch (colorspace)
@@ -702,7 +702,7 @@
         (void) FormatLocaleFile(file,"  Depth: %.20g/%.20g-bit\n",(double)
           image->depth,(double) depth);
       (void) FormatLocaleFile(file,"  Channel depth:\n");
-      if (IsImageGray(image,exception) != MagickFalse)
+      if (SetImageGray(image,exception) != MagickFalse)
         colorspace=GRAYColorspace;
       switch (colorspace)
       {