diff --git a/manifest b/manifest
index 2c90ffc99f..3ee9742e6f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Make\sthe\ssqlite3ExprCodeTarget()\sexpression\scode\sgenerator\sroutine\srobust\nin\sthe\sface\sof\sunknown\sopcodes\s-\sit\ssimply\sgenerates\sa\sNULL\svalue.
-D 2019-12-14T15:01:55.918
+C Do\snot\sset\sOP_Column\sflags\son\sthe\sinstructions\sgenerated\sby\nsqlite3ExprCodeGetColumn()\sif\sthe\sopcode\sgenerated\sis\snot\sreally\san\nOP_Column,\swhich\smight\shappen\sif\sthe\scolumn\sis\svirtual.\nFix\sfor\sticket\s[b439bfcfb7deedc6]
+D 2019-12-14T17:43:37.070
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -479,7 +479,7 @@ F src/date.c e1d8ac7102f3f283e63e13867acb0efa33861cf34f0faf4cdbaf9fa7a1eb7041
 F src/dbpage.c 135eb3b5e74f9ef74bde5cec2571192c90c86984fa534c88bf4a055076fa19b7
 F src/dbstat.c 6c407e549406c10fde9ac3987f6d734459205239ad370369bc5fcd683084a4fa
 F src/delete.c a5c59b9c0251cf7682bc52af0d64f09b1aefc6781a63592c8f1136f7b73c66e4
-F src/expr.c 530df5b8b684f94f0217115da30d292964385a83e87945bd9d7d792b08eb7d17
+F src/expr.c 7c21a77ca00cc09f500c21cdae7fb3571490c2dec70b392d9e505e81069e45ee
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 92a248ec0fa4ed8ab60c98d9b188ce173aaf218f32e7737ba77deb2a684f9847
 F src/func.c ed33e38cd642058182a31a3f518f2e34f4bbe53aa483335705c153c4d3e50b12
@@ -1022,7 +1022,7 @@ F test/fuzzer1.test 3d4c4b7e547aba5e5511a2991e3e3d07166cfbb8
 F test/fuzzer2.test a85ef814ce071293bce1ad8dffa217cbbaad4c14
 F test/fuzzerfault.test 8792cd77fd5bce765b05d0c8e01b9edcf8af8536
 F test/gcfault.test dd28c228a38976d6336a3fc42d7e5f1ad060cb8c
-F test/gencol1.test aab394862d6c14a57ff488b0ef3413ed9f3067a56955ede25b5e059188a66a41
+F test/gencol1.test 1cd2b6cfd3ba0a9fe12569db5bcd8972cb83f81586121e8d769905f3b3612879
 F test/genesis.tcl 1e2e2e8e5cc4058549a154ff1892fe5c9de19f98
 F test/having.test e4098a4b8962f9596035c3b87a8928a10648acc509f1bb8d6f96413bbf79a1b3
 F test/hexlit.test 4a6a5f46e3c65c4bf1fa06f5dd5a9507a5627751
@@ -1852,7 +1852,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 3b873029ef1903f76442445343af3786cd59ee66b0e5e0e6b76a0b6b1b5eb88a
-R 85c383a5f778e584f7e14589390faee1
+P f8e876c82a246ceed32b166f64e05dfe5ce4ab4c6820be60404109b43d36bb80
+R 3e1bcf29405c2bc765bc5cc02f705dba
 U drh
-Z d36aae0806eadd62df0ee61e4708a6ba
+Z d5d947f7a3e61dce535fe821e852738a
diff --git a/manifest.uuid b/manifest.uuid
index 49c0032f3f..a22bad27d0 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f8e876c82a246ceed32b166f64e05dfe5ce4ab4c6820be60404109b43d36bb80
\ No newline at end of file
+2401e04730a156aa48787b91af4e516406cb7635145e430be62fd16481816237
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index c6920b3c81..3552322efe 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3487,7 +3487,8 @@ int sqlite3ExprCodeGetColumn(
   assert( pParse->pVdbe!=0 );
   sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pTab, iTable, iColumn, iReg);
   if( p5 ){
-    sqlite3VdbeChangeP5(pParse->pVdbe, p5);
+    VdbeOp *pOp = sqlite3VdbeGetOp(pParse->pVdbe,-1);
+    if( pOp->opcode==OP_Column ) pOp->p5 = p5;
   }
   return iReg;
 }
diff --git a/test/gencol1.test b/test/gencol1.test
index dbcfefe61e..8d3ba648d0 100644
--- a/test/gencol1.test
+++ b/test/gencol1.test
@@ -342,7 +342,7 @@ do_execsql_test gencol1-12.10 {
   PRAGMA integrity_check;
 } {ok}
 
-# 2019-12-09 but report from Yongheng Chen
+# 2019-12-09 bug report from Yongheng Chen
 # Ensure that the SrcList_item.colUsed field is set correctly when a
 # generated column appears in the USING clause of a join.
 #
@@ -369,5 +369,19 @@ do_execsql_test gencol1-13.22 {
   SELECT 456 FROM t1 JOIN t1 USING (x,x);
 } {456}
 
+# 2019-12-14 ticket b439bfcfb7deedc6
+#
+sqlite3 db :memory:
+do_execsql_test gencol1-14.10 {
+  CREATE TABLE t0(c0 AS(1 >= 1), c1 UNIQUE AS(TYPEOF(c0)), c2);
+  INSERT INTO t0 VALUES(0);
+  REINDEX;
+  SELECT * FROM t0;
+} {1 integer 0}
+do_catchsql_test gencol1-14.10 {
+  INSERT INTO t0 VALUES(2);
+} {1 {UNIQUE constraint failed: t0.c1}}
+
+
 
 finish_test