diff --git a/phpBB/adm/style/admin.css b/phpBB/adm/style/admin.css
index d46530700f..2322b3da88 100644
--- a/phpBB/adm/style/admin.css
+++ b/phpBB/adm/style/admin.css
@@ -2691,3 +2691,12 @@ fieldset.permissions .padding {
 	word-wrap: break-word;
 	word-break: break-all;
 }
+
+/* stylelint-disable declaration-property-unit-whitelist */
+.emoji {
+	min-height: 18px;
+	min-width: 18px;
+	height: 1em;
+	width: 1em;
+}
+/* stylelint-enable declaration-property-unit-whitelist */
diff --git a/phpBB/styles/prosilver/theme/print.css b/phpBB/styles/prosilver/theme/print.css
index a3295ac367..a83270b742 100644
--- a/phpBB/styles/prosilver/theme/print.css
+++ b/phpBB/styles/prosilver/theme/print.css
@@ -137,3 +137,12 @@ div.spacer { clear: both; }
 .skip_link { display: none; }
 
 .codebox p { display: none; }
+
+/* stylelint-disable declaration-property-unit-whitelist */
+.emoji {
+	min-height: 18px;
+	min-width: 18px;
+	height: 1em;
+	width: 1em;
+}
+/* stylelint-enable declaration-property-unit-whitelist */