diff --git a/rtengine/dcraw.cc b/rtengine/dcraw.cc
index c91a73f62..a42b377d4 100644
--- a/rtengine/dcraw.cc
+++ b/rtengine/dcraw.cc
@@ -9082,8 +9082,21 @@ void CLASS adobe_coeff (const char *make, const char *model)
 
   for (i=0; i < sizeof table / sizeof *table; i++)
     if (!strncmp (name, table[i].prefix, strlen(table[i].prefix))) {
-      if (RT_blacklevel_from_constant == ThreeValBool::T && table[i].black)   black   = (ushort) table[i].black;
-      if (RT_whitelevel_from_constant == ThreeValBool::T && table[i].maximum) maximum = (ushort) table[i].maximum;
+      if (RT_blacklevel_from_constant == ThreeValBool::T && table[i].black) {
+        if (RT_canon_levels_data.black_ok) {
+          unsigned c;
+          FORC4 RT_canon_levels_data.cblack[c] = (ushort) table[i].black;
+        } else {
+          black = (ushort) table[i].black;
+        }
+      }
+      if (RT_whitelevel_from_constant == ThreeValBool::T && table[i].maximum) {
+        if (RT_canon_levels_data.white_ok) {
+          RT_canon_levels_data.white = (ushort) table[i].maximum;
+        } else {
+          maximum = (ushort) table[i].maximum;
+        }
+      }
       if (RT_matrix_from_constant == ThreeValBool::T && table[i].trans[0]) {
 	for (raw_color = j=0; j < 12; j++)
 	  ((double *)cam_xyz)[j] = table[i].trans[j] / 10000.0;