diff --git a/src/components/ScaleControls.vue b/src/components/ScaleControls.vue
index 35f8fe06..46449468 100644
--- a/src/components/ScaleControls.vue
+++ b/src/components/ScaleControls.vue
@@ -183,4 +183,10 @@ defineExpose({ focus, clearPaletteInfo })
   background: none;
   color: var(--color-text-mute);
 }
+
+p.error,
+p.warning {
+  max-height: 12em;
+  overflow-y: auto;
+}
 </style>
diff --git a/src/stores/scale.ts b/src/stores/scale.ts
index b413629a..9ae1a348 100644
--- a/src/stores/scale.ts
+++ b/src/stores/scale.ts
@@ -47,6 +47,8 @@ import { midiKeyInfo } from 'xen-midi'
 import { undoHistory } from '@/undo'
 import { useHarmonicEntropyStore } from './harmonic-entropy'
 
+const MAX_ERROR_LENGTH = 10000
+
 // Colors from #1 to #12 inclusive.
 function defaultColors(base: number) {
   return [...Array(12).keys()].map((i) => MIDI_NOTE_COLORS[mmod(base + 1 + i, 12)])
@@ -345,7 +347,7 @@ export const useScaleStore = defineStore('scale', () => {
   function warn(this: ExpressionVisitor, ...args: any[]) {
     const s = repr.bind(this)
     const message = args.map((a) => (typeof a === 'string' ? a : s(a))).join(', ')
-    warning.value = message
+    warning.value = message.slice(0, MAX_ERROR_LENGTH)
   }
   warn.__doc__ = 'Issue a warning to the user and continue execution.'
   warn.__node__ = builtinNode(warn)
@@ -530,9 +532,9 @@ export const useScaleStore = defineStore('scale', () => {
       }
     } catch (e) {
       if (e instanceof Error) {
-        error.value = e.message
+        error.value = e.message.slice(0, MAX_ERROR_LENGTH)
       } else if (typeof e === 'string') {
-        error.value = e
+        error.value = e.slice(0, MAX_ERROR_LENGTH)
       }
     }
   }