Index: src/shell.c.in
==================================================================
--- src/shell.c.in
+++ src/shell.c.in
@@ -7275,11 +7275,11 @@
   static const char const *zTabFill = "\
 INSERT INTO ColNames(name,nlen,chop,reps,suff)\
  VALUES(iif(length(?1)>0,?1,'?'),max(length(?1),1),0,0,'')\
 ";
   static const char const *zHasDupes = "\
-SELECT count(DISTINCT substring(name,1,nlen-chop)||suff)\
+SELECT count(DISTINCT (substring(name,1,nlen-chop)||suff) COLLATE NOCASE)\
  <count(name) FROM ColNames\
 ";
   static const char const *zDedoctor = "\
 WITH chopped AS ( \
  WITH RECURSIVE chopping(cpos, name, chop, nlen) AS ( \
@@ -7309,10 +7309,11 @@
 ";
   static const char const *zSetReps = "\
 UPDATE ColNames AS t SET reps=\
 (SELECT count(*) FROM ColNames d \
  WHERE substring(t.name,1,t.nlen-t.chop)=substring(d.name,1,d.nlen-d.chop)\
+ COLLATE NOCASE\
 )\
 ";
 #ifdef SQLITE_ENABLE_MATH_FUNCTIONS
   static const char const *zColDigits = "\
 SELECT CAST(ceil(log(count(*)+0.5)) AS INT) FROM ColNames \

Index: test/shell5.test
==================================================================
--- test/shell5.test
+++ test/shell5.test
@@ -497,6 +497,22 @@
     y = wye4
   z_5 = zee5
   z_6 = zee6
 Columns renamed during .import shell5.csv due to duplicates.}}
 
+do_test shell5-5.1 {
+  set out [open shell5.csv w]
+  fconfigure $out -translation lf
+  puts $out {"COW","cow","CoW","cOw"}
+  puts $out {"uuu","lll","ulu","lul"}
+  close $out
+  forcedelete test.db
+  catchcmd test.db {.import -csv shell5.csv t1
+.mode line
+SELECT * FROM t1;}
+} {1 {COW_1 = uuu
+cow_2 = lll
+CoW_3 = ulu
+cOw_4 = lul
+Columns renamed during .import shell5.csv due to duplicates.}}
+
 finish_test