diff --git a/Gopkg.lock b/Gopkg.lock
index cb992303c3..85008b5127 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -176,7 +176,7 @@
 
 [[projects]]
   branch = "master"
-  digest = "1:a59dc1530d6a590c18eca216936bace5fefc6fb4af18fb5a1cb44a9c5e0c6bc5"
+  digest = "1:80b5cf44d45e12f0e9b1665cf564b123a292850ce80128342e4c74b57a42c3b1"
   name = "github.com/vektah/gqlparser"
   packages = [
     ".",
@@ -188,7 +188,7 @@
     "validator/rules",
   ]
   pruneopts = "UT"
-  revision = "8098ed8dcb1ed81bd39ac117a2fc33b08d5eaaf0"
+  revision = "9d2a87e05c6d27ae2bab1bc914aaa9c21cf35d9a"
 
 [[projects]]
   branch = "master"
@@ -262,6 +262,7 @@
     "github.com/vektah/gqlparser",
     "github.com/vektah/gqlparser/ast",
     "github.com/vektah/gqlparser/gqlerror",
+    "github.com/vektah/gqlparser/validator",
     "golang.org/x/tools/go/loader",
     "golang.org/x/tools/imports",
     "gopkg.in/yaml.v2",
diff --git a/example/todo/todo.go b/example/todo/todo.go
index d9aa4ea7f7..087e58c2e1 100644
--- a/example/todo/todo.go
+++ b/example/todo/todo.go
@@ -1,4 +1,4 @@
-//go:generate gorunpkg github.com/vektah/gqlgen --out generated.go -v
+//go:generate gorunpkg github.com/vektah/gqlgen --out generated.go
 
 package todo
 
diff --git a/handler/graphql.go b/handler/graphql.go
index 43e953d6c9..fb943b68aa 100644
--- a/handler/graphql.go
+++ b/handler/graphql.go
@@ -12,6 +12,7 @@ import (
 	"github.com/vektah/gqlparser"
 	"github.com/vektah/gqlparser/ast"
 	"github.com/vektah/gqlparser/gqlerror"
+	"github.com/vektah/gqlparser/validator"
 )
 
 type params struct {
@@ -167,7 +168,11 @@ func GraphQL(exec graphql.ExecutableSchema, options ...Option) http.HandlerFunc
 			return
 		}
 
-		reqCtx := cfg.newRequestContext(doc, reqParams.Query, reqParams.Variables)
+		vars, err := validator.VariableValues(exec.Schema(), op, reqParams.Variables)
+		if err != nil {
+			sendError(w, http.StatusUnprocessableEntity, err)
+		}
+		reqCtx := cfg.newRequestContext(doc, reqParams.Query, vars)
 		ctx := graphql.WithRequestContext(r.Context(), reqCtx)
 
 		defer func() {
diff --git a/handler/websocket.go b/handler/websocket.go
index 40f9052bbb..8af56ae7f6 100644
--- a/handler/websocket.go
+++ b/handler/websocket.go
@@ -13,6 +13,7 @@ import (
 	"github.com/vektah/gqlparser"
 	"github.com/vektah/gqlparser/ast"
 	"github.com/vektah/gqlparser/gqlerror"
+	"github.com/vektah/gqlparser/validator"
 )
 
 const (
@@ -148,7 +149,11 @@ func (c *wsConnection) subscribe(message *operationMessage) bool {
 		return true
 	}
 
-	reqCtx := c.cfg.newRequestContext(doc, reqParams.Query, reqParams.Variables)
+	vars, err := validator.VariableValues(c.exec.Schema(), op, reqParams.Variables)
+	if err != nil {
+		c.sendError(message.ID, err)
+	}
+	reqCtx := c.cfg.newRequestContext(doc, reqParams.Query, vars)
 	ctx := graphql.WithRequestContext(c.ctx, reqCtx)
 
 	if op.Operation != ast.Subscription {