diff --git a/bijection-core/src/main/scala/com/twitter/bijection/BinaryBijections.scala b/bijection-core/src/main/scala/com/twitter/bijection/BinaryBijections.scala
index e45f8a7bc..939dc108e 100644
--- a/bijection-core/src/main/scala/com/twitter/bijection/BinaryBijections.scala
+++ b/bijection-core/src/main/scala/com/twitter/bijection/BinaryBijections.scala
@@ -30,13 +30,21 @@ case class GZippedBytes(bytes: Array[Byte]) extends AnyVal {
 
 case class GZippedBase64String(str: String) extends AnyVal
 
+object GZippedBase64String {
+  implicit val unwrap: Injection[GZippedBase64String, String] =
+    new AbstractInjection[GZippedBase64String, String] {
+      override def apply(gzbs: GZippedBase64String) = gzbs.str
+      override def invert(str: String) = attemptWhen(str)(Base64.isBase64)(GZippedBase64String(_))
+    }
+}
+
 case class Base64String(str: String) extends AnyVal
 
 object Base64String {
   implicit val unwrap: Injection[Base64String, String] =
     new AbstractInjection[Base64String, String] {
       override def apply(bs: Base64String) = bs.str
-      override def invert(str: String) = attemptWhen(str)(Base64.isBase64(_))(Base64String(_))
+      override def invert(str: String) = attemptWhen(str)(Base64.isBase64)(Base64String(_))
     }
 }
 
diff --git a/bijection-core/src/test/scala/com/twitter/bijection/BinaryBijectionLaws.scala b/bijection-core/src/test/scala/com/twitter/bijection/BinaryBijectionLaws.scala
index a32d3275c..0ef9c5ab0 100644
--- a/bijection-core/src/test/scala/com/twitter/bijection/BinaryBijectionLaws.scala
+++ b/bijection-core/src/test/scala/com/twitter/bijection/BinaryBijectionLaws.scala
@@ -17,14 +17,14 @@ limitations under the License.
 package com.twitter.bijection
 
 import java.nio.ByteBuffer
-import org.scalatest.{ PropSpec, MustMatchers }
-import org.scalatest.prop.PropertyChecks
 
-import org.scalacheck.Prop._
+import com.twitter.bijection.codec.Base64
+import org.scalacheck.Arbitrary
+import org.scalatest.MustMatchers
 
 class BinaryBijectionLaws extends CheckProperties with MustMatchers
   with BaseProperties {
-  implicit val arbBB = arbitraryViaFn[Array[Byte], ByteBuffer] { ByteBuffer.wrap(_) }
+  implicit val arbBB = arbitraryViaFn[Array[Byte], ByteBuffer] { ByteBuffer.wrap }
 
   // TODO: These are all bijections,
   property("Array[Byte] <=> ByteBuffer") {
@@ -40,10 +40,24 @@ class BinaryBijectionLaws extends CheckProperties with MustMatchers
     isInjective[Array[Byte], Base64String]
   }
 
+  property("Base64String -> String") {
+    implicit val arbB64: Arbitrary[Base64String] = arbitraryViaFn { s: String =>
+      Base64String(Base64.encodeBase64String(s.getBytes("UTF-8")))
+    }
+    isInjection[Base64String, String]
+  }
+
   property("rts Array[Byte] -> GZippedBase64String") {
     isInjective[Array[Byte], GZippedBase64String]
   }
 
+  property("GZippedBase64String -> String") {
+    implicit val arbGzB64: Arbitrary[GZippedBase64String] = arbitraryViaFn { s: String =>
+      GZippedBase64String(Base64.encodeBase64String(s.getBytes("UTF-8")))
+    }
+    isInjection[GZippedBase64String, String]
+  }
+
   implicit val optSer = JavaSerializationInjection[Option[Int]]
 
   property("java serialize Option[Int]") {