diff --git a/packages/orm/src/client/crud/dialects/base-dialect.ts b/packages/orm/src/client/crud/dialects/base-dialect.ts
index 5fae51ef5..7a75acf44 100644
--- a/packages/orm/src/client/crud/dialects/base-dialect.ts
+++ b/packages/orm/src/client/crud/dialects/base-dialect.ts
@@ -264,9 +264,12 @@ export abstract class BaseCrudDialect<Schema extends SchemaDef> {
             .with('AND', () =>
                 this.and(...enumerate(payload).map((subPayload) => this.buildFilter(model, modelAlias, subPayload))),
             )
-            .with('OR', () =>
-                this.or(...enumerate(payload).map((subPayload) => this.buildFilter(model, modelAlias, subPayload))),
-            )
+            .with('OR', () => {
+                const branches = enumerate(payload)
+                    .filter((subPayload) => !this.isAllUndefinedFilter(subPayload))
+                    .map((subPayload) => this.buildFilter(model, modelAlias, subPayload));
+                return this.or(...branches);
+            })
             .with('NOT', () => this.eb.not(this.buildCompositeFilter(model, modelAlias, 'AND', payload)))
             .exhaustive();
     }
@@ -800,6 +803,9 @@ export abstract class BaseCrudDialect<Schema extends SchemaDef> {
             if (excludeKeys.includes(op)) {
                 continue;
             }
+            if (value === undefined) {
+                continue;
+            }
             const rhs = Array.isArray(value) ? value.map(getRhs) : getRhs(value);
             const condition = match(op)
                 .with('equals', () => (rhs === null ? this.eb(lhs, 'is', null) : this.eb(lhs, '=', rhs)))
@@ -881,6 +887,10 @@ export abstract class BaseCrudDialect<Schema extends SchemaDef> {
                     continue;
                 }
 
+                if (value === undefined) {
+                    continue;
+                }
+
                 invariant(typeof value === 'string', `${key} value must be a string`);
 
                 const escapedValue = this.escapeLikePattern(value);
@@ -1162,7 +1172,8 @@ export abstract class BaseCrudDialect<Schema extends SchemaDef> {
 
         // client-level: check both uncapitalized (current) and original (backward compat) model name
         const uncapModel = lowerCaseFirst(model);
-        const omitConfig = (this.options.omit as Record<string, any> | undefined)?.[uncapModel] ??
+        const omitConfig =
+            (this.options.omit as Record<string, any> | undefined)?.[uncapModel] ??
             (this.options.omit as Record<string, any> | undefined)?.[model];
         if (omitConfig && typeof omitConfig === 'object' && typeof omitConfig[field] === 'boolean') {
             return omitConfig[field];
@@ -1299,6 +1310,14 @@ export abstract class BaseCrudDialect<Schema extends SchemaDef> {
         return this.eb.lit<SqlBool>(this.transformInput(false, 'Boolean', false) as boolean);
     }
 
+    private isAllUndefinedFilter(payload: unknown): boolean {
+        if (!payload || typeof payload !== 'object' || Array.isArray(payload)) {
+            return false;
+        }
+        const entries = Object.entries(payload);
+        return entries.length > 0 && entries.every(([, v]) => v === undefined);
+    }
+
     public isTrue(expression: Expression<SqlBool>) {
         const node = expression.toOperationNode();
         if (node.kind !== 'ValueNode') {
@@ -1357,7 +1376,9 @@ export abstract class BaseCrudDialect<Schema extends SchemaDef> {
                 const computedFields = this.options.computedFields as Record<string, any>;
                 // check both uncapitalized (current) and original (backward compat) model name
                 const computedModel = fieldDef.originModel ?? model;
-                computer = computedFields?.[lowerCaseFirst(computedModel)]?.[field] ?? computedFields?.[computedModel]?.[field];
+                computer =
+                    computedFields?.[lowerCaseFirst(computedModel)]?.[field] ??
+                    computedFields?.[computedModel]?.[field];
             }
             if (!computer) {
                 throw createConfigError(`Computed field "${field}" implementation not provided for model "${model}"`);
diff --git a/tests/e2e/orm/client-api/filter.test.ts b/tests/e2e/orm/client-api/filter.test.ts
index 36173ca2d..ff9574a41 100644
--- a/tests/e2e/orm/client-api/filter.test.ts
+++ b/tests/e2e/orm/client-api/filter.test.ts
@@ -801,5 +801,57 @@ describe('Client filter tests ', () => {
         await expect(client.user.findMany({ where: { id: undefined } })).toResolveWithLength(1);
     });
 
+    it('ignores undefined branch inside OR filters', async () => {
+        await createUser('u1@test.com', {
+            name: 'First',
+            role: 'ADMIN',
+            profile: { create: { id: 'p1', bio: 'bio1' } },
+        });
+        const user2 = await createUser('u2@test.com', {
+            name: 'Second',
+            role: 'USER',
+            profile: { create: { id: 'p2', bio: 'bio2' } },
+        });
+
+        const baseline = await client.user.findFirst({
+            where: {
+                OR: [{ id: user2.id }],
+            } as any,
+            orderBy: { createdAt: 'asc' },
+        });
+
+        const withUndefinedBranch = await client.user.findFirst({
+            where: {
+                OR: [{ id: undefined }, { id: user2.id }],
+            } as any,
+            orderBy: { createdAt: 'asc' },
+        });
+
+        const onlyUndefinedBranch = await client.user.findFirst({
+            where: {
+                OR: [{ id: undefined }],
+            } as any,
+            orderBy: { createdAt: 'asc' },
+        });
+
+        expect(baseline?.email).toBe(user2.email);
+        expect(withUndefinedBranch?.email).toBe(baseline?.email);
+        expect(onlyUndefinedBranch).toBeNull();
+    });
+
+    it('strips undefined filter operators inside OR branches', async () => {
+        await createUser('alice@test.com', { name: 'Alice', role: 'ADMIN' });
+        await createUser('bob@test.com', { name: 'Bob', role: 'USER' });
+
+        const result = await client.user.findMany({
+            where: {
+                OR: [{ name: { startsWith: 'A', contains: undefined } }],
+            } as any,
+        });
+
+        expect(result).toHaveLength(1);
+        expect(result[0]!.name).toBe('Alice');
+    });
+
     // TODO: filter for bigint, decimal, bytes
 });