diff --git a/docs/en_US/release_notes_4_26.rst b/docs/en_US/release_notes_4_26.rst
index 472cf52fb..f58489250 100644
--- a/docs/en_US/release_notes_4_26.rst
+++ b/docs/en_US/release_notes_4_26.rst
@@ -10,6 +10,7 @@ New features
 ************
 
 | `Issue #2042 <https://redmine.postgresql.org/issues/2042>`_ -  Added SQL Formatter support in Query Tool.
+| `Issue #5772 <https://redmine.postgresql.org/issues/5772>`_ -  Warn the user when connecting to a server that is older than pgAdmin supports.
 
 Housekeeping
 ************
diff --git a/web/pgadmin/browser/server_groups/servers/static/js/server.js b/web/pgadmin/browser/server_groups/servers/static/js/server.js
index 7c1b58be8..8c43a55f7 100644
--- a/web/pgadmin/browser/server_groups/servers/static/js/server.js
+++ b/web/pgadmin/browser/server_groups/servers/static/js/server.js
@@ -1195,7 +1195,16 @@ define('pgadmin.node.server', [
               pgBrowser.serverInfo || {};
             serverInfo[_data._id] = _.extend({}, _data);
 
-            Alertify.success(res.info);
+            if (_data.version < 90500) {
+              Alertify.warning(gettext('You have connected to a server version that is older ' +
+                'than is supported by pgAdmin. This may cause pgAdmin to break in strange and ' +
+                'unpredictable ways. Or a plague of frogs. Either way, you have been warned!') +
+                '<br /><br />' +
+                res.info, 0);
+            } else {
+              Alertify.success(res.info);
+            }
+
             obj.trigger('connected', obj, _item, _data);
 
             // Generate the event that server is connected
diff --git a/web/pgadmin/static/scss/_alertify.overrides.scss b/web/pgadmin/static/scss/_alertify.overrides.scss
index ca4966206..28d7d3d93 100644
--- a/web/pgadmin/static/scss/_alertify.overrides.scss
+++ b/web/pgadmin/static/scss/_alertify.overrides.scss
@@ -225,6 +225,13 @@
   @extend .ajs-text-smoothing;
 }
 
+.ajs-message.ajs-warning.ajs-visible {
+  background: $alert-warning-bg;
+  border: $border-width solid $alert-warning-color;
+  color: $alert-warning-color;
+  @extend .ajs-text-smoothing;
+}
+
 .ajs-message.ajs-visible {
   background: $alert-primary-bg;
   border: $border-width solid $alert-primary-color;
diff --git a/web/pgadmin/static/scss/resources/_default.variables.scss b/web/pgadmin/static/scss/resources/_default.variables.scss
index 2f214838d..668f18840 100644
--- a/web/pgadmin/static/scss/resources/_default.variables.scss
+++ b/web/pgadmin/static/scss/resources/_default.variables.scss
@@ -77,6 +77,8 @@ $alert-danger-bg: $color-danger-lighter !default;
 $alert-danger-color: $color-danger !default;
 $alert-success-bg: $color-success-light !default;
 $alert-success-color: $color-success !default;
+$alert-warning-bg: $color-warning !default;
+$alert-warning-color: $color-bg !default;
 
 $navbar-bg: $color-primary !default;
 $navbar-font-size: 0.925rem;
diff --git a/web/pgadmin/static/scss/resources/_theme.variables.scss.sample b/web/pgadmin/static/scss/resources/_theme.variables.scss.sample
index a07c3c178..5b6de74b3 100644
--- a/web/pgadmin/static/scss/resources/_theme.variables.scss.sample
+++ b/web/pgadmin/static/scss/resources/_theme.variables.scss.sample
@@ -32,6 +32,8 @@ $alert-danger-bg: $color-danger-lighter !default;
 $alert-danger-color: $color-danger !default;
 $alert-success-bg: $color-success-light !default;
 $alert-success-color: $color-success !default;
+$alert-warning-bg: $color-success-light !default;
+$alert-warning-color: $color-success !default;
 $negative-bg: $color-gray-light;
 $popover-bg: $color-gray-dark;
 $popover-body-color: $white;
diff --git a/web/pgadmin/static/scss/resources/dark/_theme.variables.scss b/web/pgadmin/static/scss/resources/dark/_theme.variables.scss
index a033cbfe4..d69f8a84f 100644
--- a/web/pgadmin/static/scss/resources/dark/_theme.variables.scss
+++ b/web/pgadmin/static/scss/resources/dark/_theme.variables.scss
@@ -59,6 +59,9 @@ $alert-danger-bg: $color-bg;
 $alert-danger-color: $color-danger;
 $alert-success-bg: $color-bg;
 $alert-success-color: $color-success;
+$alert-warning-bg: $color-warning;
+$alert-warning-color: $color-bg;
+
 $alert-header-fg: $color-fg;
 
 $table-bg: $color-gray-lighter;
diff --git a/web/pgadmin/static/scss/resources/high_contrast/_theme.variables.scss b/web/pgadmin/static/scss/resources/high_contrast/_theme.variables.scss
index e89bd597c..9e447ec66 100644
--- a/web/pgadmin/static/scss/resources/high_contrast/_theme.variables.scss
+++ b/web/pgadmin/static/scss/resources/high_contrast/_theme.variables.scss
@@ -61,8 +61,10 @@ $alert-primary-bg: $color-primary;
 $alert-primary-color: $color-bg;
 $alert-danger-bg: $color-danger;
 $alert-danger-color: $color-bg !important;
-$alert-success-bg̰: $color-success;
+$alert-success-bg: $color-success;
 $alert-success-color: $color-bg;
+$alert-warning-bg: $color-warning;
+$alert-warning-color: $color-bg;
 
 $alert-color-fg: $color-bg;