diff --git a/src/components/WaveformSeek.tsx b/src/components/WaveformSeek.tsx
index f0c44668..ab6eae9f 100644
--- a/src/components/WaveformSeek.tsx
+++ b/src/components/WaveformSeek.tsx
@@ -785,6 +785,10 @@ export function drawSeekbar(
     case 'particletrail': drawParticleTrail(canvas, progress, buffered, anim); break;
     case 'liquidfill':    drawLiquidFill(canvas, progress, buffered, anim); break;
     case 'retrotape':     drawRetroTape(canvas, progress, buffered, anim); break;
+    // Safety net: if a legacy or tampered persisted style sneaks past the
+    // authStore migration, fall back to the truewave renderer instead of
+    // leaving a blank canvas.
+    default:              drawWaveform(canvas, heights, progress, buffered); break;
   }
 }
 
diff --git a/src/store/authStore.ts b/src/store/authStore.ts
index decfe04a..f178c564 100644
--- a/src/store/authStore.ts
+++ b/src/store/authStore.ts
@@ -800,12 +800,18 @@ export const useAuthStore = create<AuthState>()(
           } catch { /* ignore */ }
         }
 
-        // One-time: 'waveform' style was renamed to 'truewave' (with 'pseudowave'
-        // added as the deterministic legacy variant). Existing persisted value
-        // 'waveform' should land on the new bins-based default.
-        const seekbarStyleMigrated = (state.seekbarStyle as string) === 'waveform'
-          ? { seekbarStyle: 'truewave' as SeekbarStyle }
-          : {};
+        // 'waveform' style was renamed to 'truewave' (with 'pseudowave' added
+        // as the deterministic legacy variant). Any persisted value that is
+        // not a valid SeekbarStyle (legacy 'waveform', undefined, tampered
+        // strings) lands on the new bins-based default — otherwise the
+        // dispatcher's switch finds no match and the seekbar renders blank.
+        const VALID_SEEKBAR_STYLES = new Set<string>([
+          'truewave', 'pseudowave', 'linedot', 'bar', 'thick',
+          'segmented', 'neon', 'pulsewave', 'particletrail', 'liquidfill', 'retrotape',
+        ]);
+        const seekbarStyleMigrated = VALID_SEEKBAR_STYLES.has(state.seekbarStyle as string)
+          ? {}
+          : { seekbarStyle: 'truewave' as SeekbarStyle };
 
         const st = state as {
           loudnessTargetLufs?: unknown;