diff --git a/test/plugins/auth/ldap.js b/test/plugins/auth/ldap.js
index 6ae06118..46703de6 100644
--- a/test/plugins/auth/ldap.js
+++ b/test/plugins/auth/ldap.js
@@ -124,6 +124,8 @@ function testLdapAuth() {
 }
 
 describe("LDAP authentication plugin", function() {
+	// Increase timeout due to unpredictable I/O on CI services
+	this.timeout(process.env.CI ? 25000 : 5000);
 	this.slow(200);
 
 	let server;
diff --git a/test/plugins/link.js b/test/plugins/link.js
index ae0bbfaf..8da6c133 100644
--- a/test/plugins/link.js
+++ b/test/plugins/link.js
@@ -7,6 +7,8 @@ const Helper = require("../../src/helper");
 const link = require("../../src/plugins/irc-events/link.js");
 
 describe("Link plugin", function() {
+	// Increase timeout due to unpredictable I/O on CI services
+	this.timeout(process.env.CI ? 25000 : 5000);
 	this.slow(200);
 
 	let app;
diff --git a/test/plugins/sqlite.js b/test/plugins/sqlite.js
index 3b5fcc9a..6051632d 100644
--- a/test/plugins/sqlite.js
+++ b/test/plugins/sqlite.js
@@ -8,6 +8,9 @@ const Helper = require("../../src/helper");
 const MessageStorage = require("../../src/plugins/messageStorage/sqlite.js");
 
 describe("SQLite Message Storage", function() {
+	// Increase timeout due to unpredictable I/O on CI services
+	this.timeout(process.env.CI ? 25000 : 5000);
+
 	const expectedPath = path.join(Helper.getHomePath(), "logs", "testUser.sqlite3");
 	let store;
 
diff --git a/test/plugins/storage.js b/test/plugins/storage.js
index dc6d8ab1..12f82ef2 100644
--- a/test/plugins/storage.js
+++ b/test/plugins/storage.js
@@ -9,6 +9,8 @@ const Helper = require("../../src/helper");
 const link = require("../../src/plugins/irc-events/link.js");
 
 describe("Image storage", function() {
+	// Increase timeout due to unpredictable I/O on CI services
+	this.timeout(process.env.CI ? 25000 : 5000);
 	this.slow(200);
 
 	const testImagePath = path.resolve(__dirname, "../../client/img/logo-grey-bg-120x120px.png");
diff --git a/test/server.js b/test/server.js
index cc9340a2..cf6ebbe3 100644
--- a/test/server.js
+++ b/test/server.js
@@ -7,7 +7,7 @@ const got = require("got");
 const io = require("socket.io-client");
 
 describe("Server", function() {
-	// Travis is having issues with slow workers and thus tests timeout
+	// Increase timeout due to unpredictable I/O on CI services
 	this.timeout(process.env.CI ? 25000 : 5000);
 
 	let server;