diff --git a/index.js b/index.js
index 1dbfaacb..42cfcab0 100644
--- a/index.js
+++ b/index.js
@@ -18,6 +18,9 @@ function Multer (options) {
   }
 
   this.limits = options.limits
+  if (this.limits && this.limits.fileSize != null && !Number.isInteger(this.limits.fileSize)) {
+    throw new TypeError('Expected limits.fileSize to be an integer')
+  }
   this.preservePath = options.preservePath
   this.defParamCharset = options.defParamCharset || 'latin1'
   this.fileFilter = options.fileFilter || allowAll
diff --git a/test/error-handling.js b/test/error-handling.js
index 597e8039..30b53b10 100644
--- a/test/error-handling.js
+++ b/test/error-handling.js
@@ -459,4 +459,16 @@ describe('Error Handling', function () {
       done()
     })
   })
+
+  it('should throw TypeError when fileSize limit is a float', function () {
+    assert.throws(function () {
+      multer({ limits: { fileSize: 1024.5 } })
+    }, TypeError)
+  })
+
+  it('should accept integer fileSize limit', function () {
+    assert.doesNotThrow(function () {
+      multer({ limits: { fileSize: 1024 } })
+    })
+  })
 })