diff --git a/spec/keytar-spec.js b/spec/keytar-spec.js
index d9318b64..53ba627a 100644
--- a/spec/keytar-spec.js
+++ b/spec/keytar-spec.js
@@ -9,6 +9,11 @@ describe("keytar", function() {
   var account2 = 'buster2'
   var password2 = 'secret2'
 
+  var object = {}
+  object.toString = function () {
+    throw new Error("Whoops! Time to seg fault")
+  }
+
   beforeEach(async function() {
     await keytar.deletePassword(service, account),
     await keytar.deletePassword(service, account2)
@@ -34,6 +39,52 @@ describe("keytar", function() {
       assert.equal(await keytar.getPassword(service, account), null)
     })
 
+    describe("error handling", function () {
+      describe('setPassword', () => {
+        it("handles when an object is provided for service", async function () {
+          try {
+            await keytar.setPassword(object, account, password)
+          } catch (err) {
+            assert.equal(err.message, "Parameter 'service' must be a string")
+          }
+        })
+
+        it("handles when an object is provided for username", async function () {
+          try {
+            await keytar.setPassword(service, object, password)
+          } catch (err) {
+            assert.equal(err.message, "Parameter 'username' must be a string")
+          }
+        })
+
+        it("handles when an object is provided for password", async function () {
+          try {
+            await keytar.setPassword(service, account, object)
+          } catch (err) {
+            assert.equal(err.message, "Parameter 'password' must be a string")
+          }
+        })
+      })
+
+      describe('getPassword', () => {
+        it("handles when an object is provided for service", async function () {
+          try {
+            await keytar.getPassword(object, account)
+          } catch (err) {
+            assert.equal(err.message, "Parameter 'service' must be a string")
+          }
+        })
+
+        it("handles when an object is provided for username", async function () {
+          try {
+            await keytar.getPassword(service, object)
+          } catch (err) {
+            assert.equal(err.message, "Parameter 'username' must be a string")
+          }
+        })
+      })
+    })
+
     describe("Unicode support", function() {
       const service = "se®vi\u00C7e"
       const account = "shi\u0191\u2020ke\u00A5"
@@ -59,6 +110,24 @@ describe("keytar", function() {
     it("yields false when the password didn't exist", async function() {
       assert.equal(await keytar.deletePassword(service, account), false)
     })
+
+    describe("error handling", function () {
+      it("handles when an object is provided for service", async function () {
+        try {
+          await keytar.deletePassword(object, account)
+        } catch (err) {
+          assert.equal(err.message, "Parameter 'service' must be a string")
+        }
+      })
+
+      it("handles when an object is provided for username", async function () {
+        try {
+          await keytar.deletePassword(service, object)
+        } catch (err) {
+          assert.equal(err.message, "Parameter 'username' must be a string")
+        }
+      })
+    })
   })
 
   describe("findPassword(service)", function() {
@@ -71,6 +140,14 @@ describe("keytar", function() {
     it("yields null when no password can be found", async function() {
       assert.equal(await keytar.findPassword(service), null)
     })
+
+    it("handles when an object is provided for service", async function () {
+      try {
+        await keytar.findPassword(object)
+      } catch (err) {
+        assert.equal(err.message, "Parameter 'service' must be a string")
+      }
+    })
   })
 
   describe('findCredentials(service)', function() {
@@ -92,6 +169,14 @@ describe("keytar", function() {
       assert.deepEqual([], accounts)
     })
 
+    it("handles when an object is provided for service", async function () {
+      try {
+        await keytar.findCredentials(object)
+      } catch (err) {
+        assert.equal(err.message, "Parameter 'service' must be a string")
+      }
+    })
+
     describe("Unicode support", function() {
       const service = "se®vi\u00C7e"
       const account = "shi\u0191\u2020ke\u00A5"
diff --git a/src/main.cc b/src/main.cc
index 3218941e..637f32f4 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -4,10 +4,27 @@
 namespace {
 
 NAN_METHOD(SetPassword) {
+  if (!info[0]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'service' must be a string");
+    return;
+  }
+
   Nan::Utf8String serviceNan(info[0]);
   std::string service(*serviceNan, serviceNan.length());
+
+  if (!info[1]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'username' must be a string");
+    return;
+  }
+
   Nan::Utf8String usernameNan(info[1]);
   std::string username(*usernameNan, usernameNan.length());
+
+  if (!info[2]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'password' must be a string");
+    return;
+  }
+
   Nan::Utf8String passwordNan(info[2]);
   std::string password(*passwordNan, passwordNan.length());
 
@@ -20,8 +37,19 @@ NAN_METHOD(SetPassword) {
 }
 
 NAN_METHOD(GetPassword) {
+  if (!info[0]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'service' must be a string");
+    return;
+  }
+
   Nan::Utf8String serviceNan(info[0]);
   std::string service(*serviceNan, serviceNan.length());
+
+  if (!info[1]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'username' must be a string");
+    return;
+  }
+
   Nan::Utf8String usernameNan(info[1]);
   std::string username(*usernameNan, usernameNan.length());
 
@@ -33,8 +61,19 @@ NAN_METHOD(GetPassword) {
 }
 
 NAN_METHOD(DeletePassword) {
+  if (!info[0]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'service' must be a string");
+    return;
+  }
+
   Nan::Utf8String serviceNan(info[0]);
   std::string service(*serviceNan, serviceNan.length());
+
+  if (!info[1]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'username' must be a string");
+    return;
+  }
+
   Nan::Utf8String usernameNan(info[1]);
   std::string username(*usernameNan, usernameNan.length());
 
@@ -46,6 +85,11 @@ NAN_METHOD(DeletePassword) {
 }
 
 NAN_METHOD(FindPassword) {
+  if (!info[0]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'service' must be a string");
+    return;
+  }
+
   Nan::Utf8String serviceNan(info[0]);
   std::string service(*serviceNan, serviceNan.length());
 
@@ -56,6 +100,11 @@ NAN_METHOD(FindPassword) {
 }
 
 NAN_METHOD(FindCredentials) {
+  if (!info[0]->IsString()) {
+    Nan::ThrowTypeError("Parameter 'service' must be a string");
+    return;
+  }
+
   Nan::Utf8String serviceNan(info[0]);
   std::string service(*serviceNan, serviceNan.length());