diff --git a/app/assets/stylesheets/pages/boards.scss b/app/assets/stylesheets/pages/boards.scss
index 750d2c8b990f6c6f2b3d256ed9d7eb364936ec9d..5de53892fac5598f7bfc29f38e116d7e396ef450 100644
--- a/app/assets/stylesheets/pages/boards.scss
+++ b/app/assets/stylesheets/pages/boards.scss
@@ -80,7 +80,6 @@
   overflow-x: scroll;
   white-space: nowrap;
   min-height: 200px;
-  display: flex;
 
   @include media-breakpoint-only(sm) {
     height: calc(100vh - #{$issue-board-list-difference-sm});
@@ -111,15 +110,17 @@
 
 .board {
   display: inline-block;
-  flex: 1;
-  min-width: 300px;
-  max-width: 400px;
+  width: calc(85vw - 15px);
   height: 100%;
   padding-right: ($gl-padding / 2);
   padding-left: ($gl-padding / 2);
   white-space: normal;
   vertical-align: top;
 
+  @include media-breakpoint-up(sm) {
+    width: 400px;
+  }
+
   &.is-expandable {
     .board-header {
       cursor: pointer;
@@ -127,8 +128,6 @@
   }
 
   &.is-collapsed {
-    flex: none;
-    min-width: 0;
     width: 50px;
 
     .board-header {
diff --git a/changelogs/unreleased/rosulk-patch-12.yml b/changelogs/unreleased/rosulk-patch-12.yml
deleted file mode 100644
index 9637c88d1a4e74e6becd1f2db84adcea10a22268..0000000000000000000000000000000000000000
--- a/changelogs/unreleased/rosulk-patch-12.yml
+++ /dev/null
@@ -1,5 +0,0 @@
----
-title: Flex issue board columns
-merge_request: 19250
-author: Roman Rosluk
-type: changed