diff --git a/mysql-test/main/statistics_json.result b/mysql-test/main/statistics_json.result
index 76a23f66c09..3e158d3ec12 100644
--- a/mysql-test/main/statistics_json.result
+++ b/mysql-test/main/statistics_json.result
@@ -4482,7 +4482,6 @@ set analyze_sample_percentage=@save_analyze_sample_percentage;
 set histogram_size=@save_histogram_size;
 set use_stat_tables=@save_use_stat_tables;
 set @@global.histogram_size=@save_histogram_size;
-drop table if exists t1;
 set @save_histogram_type=@@histogram_type;
 set @save_histogram_size=@@histogram_size;
 call mtr.add_suppression("Failed to parse histogram for table .*");
@@ -8746,4 +8745,10 @@ analyze select * from t1 where col1 < '"😺';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10.00	50.00	50.00	Using where
 drop table t1;
+#
+# MDEV-41603 DECODE_HISTOGRAM crashes when decoding JSON_HB
+#
+SELECT DECODE_HISTOGRAM('JSON_HB', REPEAT('A',80));
+DECODE_HISTOGRAM('JSON_HB', REPEAT('A',80))
+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 # End of 10.11 tests
diff --git a/mysql-test/main/statistics_json.test b/mysql-test/main/statistics_json.test
index c57e9d113bb..570f3afbdc7 100644
--- a/mysql-test/main/statistics_json.test
+++ b/mysql-test/main/statistics_json.test
@@ -8,9 +8,6 @@ let $histogram_type_override='JSON_HB';
 --source include/have_innodb.inc
 --source include/have_stat_tables.inc
 --source include/have_sequence.inc
---disable_warnings
-drop table if exists t1;
---enable_warnings
 
 set @save_histogram_type=@@histogram_type;
 set @save_histogram_size=@@histogram_size;
@@ -684,4 +681,9 @@ analyze select * from t1 where col1 < '"😺';
 
 drop table t1;
 
+--echo #
+--echo # MDEV-41603 DECODE_HISTOGRAM crashes when decoding JSON_HB
+--echo #
+SELECT DECODE_HISTOGRAM('JSON_HB', REPEAT('A',80));
+
 --echo # End of 10.11 tests
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 81735f2cd6a..a61eff4dc36 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -566,6 +566,13 @@ String *Item_func_decode_histogram::val_str(String *str)
   }
   type--;
 
+  if (type == JSON_HB)
+  {
+    res= args[1]->val_str(str);
+    null_value= res == 0;
+    return res;
+  }
+
   tmp.length(0);
   if (!(res= args[1]->val_str(&tmp)))
   {
@@ -573,13 +580,6 @@ String *Item_func_decode_histogram::val_str(String *str)
     return 0;
   }
 
-  if (type == JSON_HB)
-  {
-    // It's a JSON histogram. Return it as-is.
-    null_value= 0;
-    return res;
-  }
-
   if (type == DOUBLE_PREC_HB && res->length() % 2 != 0)
     res->length(res->length() - 1); // one byte is unused