diff --git a/src/types/relying-party-options.spec.ts b/src/types/relying-party-options.spec.ts
index ffddd656..8a82b141 100644
--- a/src/types/relying-party-options.spec.ts
+++ b/src/types/relying-party-options.spec.ts
@@ -19,6 +19,54 @@ describe('RelyingPartyOptions', () => {
     expect(result.success).toBe(true);
   });
 
+  it('should fail validation with a negative pollingIntervalInMilliseconds', () => {
+    const invalidData = {
+      url: 'https://example.com',
+      connectionOptions: {
+        pollingIntervalInMilliseconds: -500
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(invalidData);
+    expect(result.success).toBe(false);
+  });
+
+  it('should fail validation with zero pollingIntervalInMilliseconds', () => {
+    const invalidData = {
+      url: 'https://example.com',
+      connectionOptions: {
+        pollingIntervalInMilliseconds: 0
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(invalidData);
+    expect(result.success).toBe(false);
+  });
+
+  it('should fail validation with a zero timeoutInMilliseconds', () => {
+    const invalidData = {
+      url: 'https://example.com',
+      connectionOptions: {
+        timeoutInMilliseconds: 0
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(invalidData);
+    expect(result.success).toBe(false);
+  });
+
+  it('should fail validation with a negative timeoutInMilliseconds', () => {
+    const invalidData = {
+      url: 'https://example.com',
+      connectionOptions: {
+        timeoutInMilliseconds: -120000
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(invalidData);
+    expect(result.success).toBe(false);
+  });
+
   it('should validate with correct relying party options and string window options', () => {
     const validData = {
       url: 'https://example.com',
@@ -52,6 +100,48 @@ describe('RelyingPartyOptions', () => {
     expect(result.success).toBe(false);
   });
 
+  it('should fail validation with zero width for the signer window', () => {
+    const invalidData = {
+      url: 'https://example.com',
+      windowOptions: {
+        position: 'center',
+        width: 0,
+        height: 300
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(invalidData);
+    expect(result.success).toBe(false);
+  });
+
+  it('should fail validation with zero height for the signer window', () => {
+    const invalidData = {
+      url: 'https://example.com',
+      windowOptions: {
+        position: 'center',
+        width: 400,
+        height: 0
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(invalidData);
+    expect(result.success).toBe(false);
+  });
+
+  it('should pass validation with positive width and height for the signer window', () => {
+    const validData = {
+      url: 'https://example.com',
+      windowOptions: {
+        position: 'center',
+        width: 400,
+        height: 300
+      }
+    };
+
+    const result = RelyingPartyOptionsSchema.safeParse(validData);
+    expect(result.success).toBe(true);
+  });
+
   it('should fail validation with incorrect connectionOptions object', () => {
     const invalidData = {
       url: 'https://example.com',
diff --git a/src/types/relying-party-options.ts b/src/types/relying-party-options.ts
index 3f167d99..a930dc61 100644
--- a/src/types/relying-party-options.ts
+++ b/src/types/relying-party-options.ts
@@ -3,18 +3,20 @@ import {z} from 'zod';
 const ConnectionOptionsSchema = z.object({
   /**
    * Specifies the interval in milliseconds at which the signer is checked (polled) to determine if it is ready.
+   * Must be a positive number.
    *
    * @default 500 - The default polling interval is set to 500 milliseconds.
    */
-  pollingIntervalInMilliseconds: z.number().optional(),
+  pollingIntervalInMilliseconds: z.number().positive().optional(),
 
   /**
    * Specifies the maximum duration in milliseconds for attempting to establish a connection to the signer.
    * If the connection is not established within this duration, the process will time out.
+   * Must be a positive number.
    *
    * @default 120_000 - The default timeout is set to 120,000 milliseconds (2 minutes).
    */
-  timeoutInMilliseconds: z.number().optional()
+  timeoutInMilliseconds: z.number().positive().optional()
 });
 
 export type ConnectionOptions = z.infer<typeof ConnectionOptionsSchema>;
@@ -26,14 +28,14 @@ const WindowOptionsSchema = z.object({
   position: z.enum(['top-right', 'center']),
 
   /**
-   * Specifies the width of the signer window.
+   * Specifies a width greater than zero of the signer window.
    */
-  width: z.number(),
+  width: z.number().positive(),
 
   /**
-   * Specifies the height of the signer window.
+   * Specifies a height greater than zero of the signer window.
    */
-  height: z.number(),
+  height: z.number().positive(),
 
   /**
    * Optional features for the signer Window object.
diff --git a/src/types/relying-party-request.specs.ts b/src/types/relying-party-request.spec.ts
similarity index 62%
rename from src/types/relying-party-request.specs.ts
rename to src/types/relying-party-request.spec.ts
index 6634ca51..75a10e18 100644
--- a/src/types/relying-party-request.specs.ts
+++ b/src/types/relying-party-request.spec.ts
@@ -26,5 +26,23 @@ describe('RelyingPartyRequests', () => {
       const result = RelyingPartyRequestOptionsSchema.safeParse(invalidData);
       expect(result.success).toBe(false);
     });
+
+    it('should fail validation with a non-positive timeoutInMilliseconds', () => {
+      const invalidData = {
+        timeoutInMilliseconds: -500
+      };
+
+      const result = RelyingPartyRequestOptionsSchema.safeParse(invalidData);
+      expect(result.success).toBe(false);
+    });
+
+    it('should fail validation with a zero timeoutInMilliseconds', () => {
+      const invalidData = {
+        timeoutInMilliseconds: 0
+      };
+
+      const result = RelyingPartyRequestOptionsSchema.safeParse(invalidData);
+      expect(result.success).toBe(false);
+    });
   });
 });
diff --git a/src/types/relying-party-requests.ts b/src/types/relying-party-requests.ts
index 70b3a785..712cb878 100644
--- a/src/types/relying-party-requests.ts
+++ b/src/types/relying-party-requests.ts
@@ -5,8 +5,9 @@ export const RelyingPartyRequestOptionsTimeoutSchema = z.object({
   /**
    * Specifies the maximum duration in milliseconds for attempting to request an interaction with the relying party.
    * If the relying party does not answer within this duration, the process will time out.
+   * Must be a positive number.
    */
-  timeoutInMilliseconds: z.number()
+  timeoutInMilliseconds: z.number().positive()
 });
 
 export const RelyingPartyRequestOptionsSchema = z
diff --git a/src/types/signer-sessions.spec.ts b/src/types/signer-sessions.spec.ts
index 8bb503a9..b3f3a233 100644
--- a/src/types/signer-sessions.spec.ts
+++ b/src/types/signer-sessions.spec.ts
@@ -48,6 +48,26 @@ describe('Signer-sessions', () => {
     expect(() => SessionPermissionsSchema.parse(invalidData)).toThrow();
   });
 
+  it('should fail validation with a negative createdAt', () => {
+    const invalidData = {
+      scopes,
+      createdAt: -1000,
+      updatedAt: Date.now()
+    };
+
+    expect(() => SessionPermissionsSchema.parse(invalidData)).toThrow();
+  });
+
+  it('should fail validation with a zero createdAt', () => {
+    const invalidData = {
+      scopes,
+      createdAt: 0,
+      updatedAt: Date.now()
+    };
+
+    expect(() => SessionPermissionsSchema.parse(invalidData)).toThrow();
+  });
+
   it('should fail validation if updatedAt is not a number', () => {
     const invalidData = {
       scopes,
@@ -67,6 +87,26 @@ describe('Signer-sessions', () => {
     expect(() => SessionPermissionsSchema.parse(invalidData)).toThrow();
   });
 
+  it('should fail validation with a negative updatedAt', () => {
+    const invalidData = {
+      scopes,
+      createdAt: Date.now(),
+      updatedAt: -1000
+    };
+
+    expect(() => SessionPermissionsSchema.parse(invalidData)).toThrow();
+  });
+
+  it('should fail validation with a zero updatedAt', () => {
+    const invalidData = {
+      scopes,
+      createdAt: Date.now(),
+      updatedAt: 0
+    };
+
+    expect(() => SessionPermissionsSchema.parse(invalidData)).toThrow();
+  });
+
   it('should fail validation if scopes is missing', () => {
     const invalidData = {
       createdAt: Date.now(),
diff --git a/src/types/signer-sessions.ts b/src/types/signer-sessions.ts
index 52ae790a..c3fe1558 100644
--- a/src/types/signer-sessions.ts
+++ b/src/types/signer-sessions.ts
@@ -2,8 +2,8 @@ import {z} from 'zod';
 import {IcrcScopeSchema} from './icrc-responses';
 
 export const SessionTimestampsSchema = z.object({
-  createdAt: z.number(),
-  updatedAt: z.number()
+  createdAt: z.number().positive(),
+  updatedAt: z.number().positive()
 });
 
 export const SessionIcrcScopeSchema = IcrcScopeSchema.merge(SessionTimestampsSchema);