diff --git a/browser/extensions/webcompat/data/interventions.json b/browser/extensions/webcompat/data/interventions.json
index 6ef346614f7d..add5f01d9122 100644
--- a/browser/extensions/webcompat/data/interventions.json
+++ b/browser/extensions/webcompat/data/interventions.json
@@ -2933,6 +2933,23 @@
       }
     ]
   },
+  "1918995": {
+    "label": "calculator.net",
+    "bugs": {
+      "1918995": {
+        "issue": "user-interface-frustration",
+        "matches": ["*://www.calculator.net/*"]
+      }
+    },
+    "interventions": [
+      {
+        "platforms": ["android"],
+        "content_scripts": {
+          "css": ["bug1918995-calculator.net-hide-copypaste-ui-for-buttons.css"]
+        }
+      }
+    ]
+  },
   "1935598": {
     "label": "testbook.com",
     "bugs": {
diff --git a/browser/extensions/webcompat/injections/css/bug1918995-calculator.net-hide-copypaste-ui-for-buttons.css b/browser/extensions/webcompat/injections/css/bug1918995-calculator.net-hide-copypaste-ui-for-buttons.css
new file mode 100644
index 000000000000..618204fde5cf
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1918995-calculator.net-hide-copypaste-ui-for-buttons.css
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * calculator.net - Text-selection UI interrupts users
+ * Bug #1918995 - https://bugzilla.mozilla.org/show_bug.cgi?id=1918995
+ * WebCompat issue #141610 - https://webcompat.com/issues/141610
+ *
+ * The text-selection copy/paste UI is not disabled on the keys of the
+ * calculator, which can lead to frustration. This CSS prevents that.
+ */
+#sciout :has(.scinm) {
+  user-select: none;
+}