diff --git a/Sources/ApolloCodegenLib/ApolloCodegenOptions.swift b/Sources/ApolloCodegenLib/ApolloCodegenOptions.swift
index 47e33be997..9fb608b5f1 100644
--- a/Sources/ApolloCodegenLib/ApolloCodegenOptions.swift
+++ b/Sources/ApolloCodegenLib/ApolloCodegenOptions.swift
@@ -53,6 +53,7 @@ public struct ApolloCodegenOptions {
   }
   
   let codegenEngine: CodeGenerationEngine
+  let customScalarsPrefix: String?
   let includes: String
   let mergeInFieldsFromFragmentSpreads: Bool
   let namespace: String?
@@ -84,6 +85,7 @@ public struct ApolloCodegenOptions {
   ///  - urlToSchemaFile: The URL to your schema file.
   ///  - downloadTimeout: The maximum time to wait before indicating that the download timed out, in seconds. Defaults to 30 seconds.
   public init(codegenEngine: CodeGenerationEngine = .default,
+              customScalarsPrefix: String? = nil,
               includes: String = "./**/*.graphql",
               mergeInFieldsFromFragmentSpreads: Bool = true,
               modifier: AccessModifier = .public,
@@ -97,6 +99,7 @@ public struct ApolloCodegenOptions {
               urlToSchemaFile: URL,
               downloadTimeout: Double = 30.0) {
     self.codegenEngine = codegenEngine
+    self.customScalarsPrefix = customScalarsPrefix
     self.includes = includes
     self.mergeInFieldsFromFragmentSpreads = mergeInFieldsFromFragmentSpreads
     self.modifier = modifier
@@ -153,6 +156,10 @@ public struct ApolloCodegenOptions {
       "--localSchemaFile='\(self.urlToSchemaFile.path)'"
     ]
     
+    if let customScalarsPrefix = self.customScalarsPrefix {
+      arguments.append("--customScalarsPrefix=\(customScalarsPrefix)")
+    }
+    
     if let namespace = self.namespace {
       arguments.append("--namespace=\(namespace)")
     }
diff --git a/Tests/ApolloCodegenTests/ApolloCodegenTests.swift b/Tests/ApolloCodegenTests/ApolloCodegenTests.swift
index c154e96b9c..89cd5536ba 100644
--- a/Tests/ApolloCodegenTests/ApolloCodegenTests.swift
+++ b/Tests/ApolloCodegenTests/ApolloCodegenTests.swift
@@ -32,6 +32,7 @@ class ApolloCodegenTests: XCTestCase {
     
     XCTAssertEqual(options.includes, "./**/*.graphql")
     XCTAssertTrue(options.mergeInFieldsFromFragmentSpreads)
+    XCTAssertNil(options.customScalarsPrefix)
     XCTAssertNil(options.namespace)
     XCTAssertNil(options.only)
     XCTAssertNil(options.operationIDsURL)
@@ -58,6 +59,7 @@ class ApolloCodegenTests: XCTestCase {
   }
   
   func testCreatingOptionsWithAllParameters() throws {
+    let customScalarsPrefix = "Scalar"
     let sourceRoot = CodegenTestHelper.sourceRootURL()
     let output = sourceRoot.appendingPathComponent("API")
     let schema = sourceRoot.appendingPathComponent("schema.json")
@@ -66,6 +68,7 @@ class ApolloCodegenTests: XCTestCase {
     let namespace = "ANameSpace"
     
     let options = ApolloCodegenOptions(codegenEngine: .swiftExperimental,
+                                       customScalarsPrefix: customScalarsPrefix,
                                        includes: "*.graphql",
                                        mergeInFieldsFromFragmentSpreads: false,
                                        modifier: .internal,
@@ -91,6 +94,7 @@ class ApolloCodegenTests: XCTestCase {
     XCTAssertEqual(options.urlToSchemaFile, schema)
     XCTAssertTrue(options.omitDeprecatedEnumCases)
     XCTAssertEqual(options.modifier, .internal)
+    XCTAssertEqual(options.customScalarsPrefix, customScalarsPrefix)
     
     
     XCTAssertEqual(options.arguments, [
@@ -99,7 +103,8 @@ class ApolloCodegenTests: XCTestCase {
       "--addTypename",
       "--includes='*.graphql'",
       "--localSchemaFile='\(schema.path)'",
-      "--namespace=\(namespace)",
+      "--customScalarsPrefix=Scalar",
+      "--namespace=ANameSpace",
       "--only='\(only.path)'",
       "--operationIdsPath='\(operationIDsURL.path)'",
       "--omitDeprecatedEnumCases",