diff --git a/mysql-test/r/selectivity.result b/mysql-test/r/selectivity.result
index ba7c9c59361..3f5db42d341 100644
--- a/mysql-test/r/selectivity.result
+++ b/mysql-test/r/selectivity.result
@@ -1635,3 +1635,37 @@ set @@use_stat_tables= @save_use_stat_tables;
 set @@optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 drop table t1;
 drop function f1;
+#
+# MDEV-19834 Selectivity of an equality condition discounted twice
+#
+set @@optimizer_use_condition_selectivity=4;
+set @@use_stat_tables='preferably';
+create table t1 (a int, b int, key (b), key (a));
+insert into t1
+select (rand(1)*1000)/10, (rand(1001)*1000)/50 from seq_1_to_1000;
+analyze table t1 ;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	Table is already up to date
+# Check what info the optimizer has about selectivities
+explain extended select * from t1 use index () where a in (17,51,5);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	2.97	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` USE INDEX () where (`test`.`t1`.`a` in (17,51,5))
+explain extended select * from t1 use index () where b=2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	4.76	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` USE INDEX () where (`test`.`t1`.`b` = 2)
+# Now, the equality is used for ref access, while the range condition
+# gives selectivity data
+explain extended select * from t1 where a in (17,51,5) and b=2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ref	b,a	b	5	const	58	2.90	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where ((`test`.`t1`.`b` = 2) and (`test`.`t1`.`a` in (17,51,5)))
+drop table t1;
+set use_stat_tables= @save_use_stat_tables;
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
+# End of 10.1 tests
diff --git a/mysql-test/t/selectivity.test b/mysql-test/t/selectivity.test
index 3df49456332..f1c9d6b31b8 100644
--- a/mysql-test/t/selectivity.test
+++ b/mysql-test/t/selectivity.test
@@ -1,4 +1,5 @@
 --source include/have_stat_tables.inc
+--source include/have_sequence.inc
 
 --disable_warnings
 drop table if exists t0,t1,t2,t3;
@@ -1102,3 +1103,26 @@ set @@optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectiv
 drop table t1;
 drop function f1;
 
+--echo #
+--echo # MDEV-19834 Selectivity of an equality condition discounted twice
+--echo #
+set @@optimizer_use_condition_selectivity=4;
+set @@use_stat_tables='preferably';
+create table t1 (a int, b int, key (b), key (a));
+insert into t1
+select (rand(1)*1000)/10, (rand(1001)*1000)/50 from seq_1_to_1000;
+analyze table t1 ;
+
+--echo # Check what info the optimizer has about selectivities
+explain extended select * from t1 use index () where a in (17,51,5);
+explain extended select * from t1 use index () where b=2;
+
+--echo # Now, the equality is used for ref access, while the range condition
+--echo # gives selectivity data
+explain extended select * from t1 where a in (17,51,5) and b=2;
+drop table t1;
+
+set use_stat_tables= @save_use_stat_tables;
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
+--echo # End of 10.1 tests
+
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index fb8e4755b1d..29fc3f80ed0 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -7618,6 +7618,7 @@ double table_cond_selectivity(JOIN *join, uint idx, JOIN_TAB *s,
     KEYUSE *keyuse= pos->key;
     KEYUSE *prev_ref_keyuse= keyuse;
     uint key= keyuse->key;
+    bool used_range_selectivity= false;
     
     /*
       Check if we have a prefix of key=const that matches a quick select.
@@ -7643,6 +7644,7 @@ double table_cond_selectivity(JOIN *join, uint idx, JOIN_TAB *s,
           keyparts++;
         }
         sel /= (double)table->quick_rows[key] / (double) table->stat_records();
+        used_range_selectivity= true;
       }
     }
     
@@ -7678,13 +7680,14 @@ double table_cond_selectivity(JOIN *join, uint idx, JOIN_TAB *s,
           if (keyparts > keyuse->keypart)
 	  {
             /* Ok this is the keyuse that will be used for ref access */
-            uint fldno;
-            if (is_hash_join_key_no(key))
-	      fldno= keyuse->keypart;
-            else
-              fldno= table->key_info[key].key_part[keyparts-1].fieldnr - 1;
-            if (keyuse->val->const_item())
+            if (!used_range_selectivity && keyuse->val->const_item())
             { 
+              uint fldno;
+              if (is_hash_join_key_no(key))
+                fldno= keyuse->keypart;
+              else
+                fldno= table->key_info[key].key_part[keyparts-1].fieldnr - 1;
+
               if (table->field[fldno]->cond_selectivity > 0)
 	      {            
                 sel /= table->field[fldno]->cond_selectivity;