diff --git a/src/hspec/Main.hs b/src/hspec/Main.hs
--- a/src/hspec/Main.hs
+++ b/src/hspec/Main.hs
@@ -18,14 +18,17 @@
 
 main :: IO ()
 main = hspec do
+  describe "String" do
+    allUptoIsMany (Proxy @String) (Proxy @TextBuilder)
+
   describe "Data.Text.Text" do
-    allIs (Proxy @Data.Text.Text) (Proxy @TextBuilder)
+    allUptoIs (Proxy @Data.Text.Text) (Proxy @TextBuilder)
 
   describe "Data.Text.Lazy.Text" do
-    allIs (Proxy @Data.Text.Lazy.Text) (Proxy @TextBuilder)
+    allUptoIs (Proxy @Data.Text.Lazy.Text) (Proxy @TextBuilder)
 
   describe "Data.Text.Lazy.Builder.Builder" do
-    allIs (Proxy @Data.Text.Lazy.Builder.Builder) (Proxy @TextBuilder)
+    allUptoIs (Proxy @Data.Text.Lazy.Builder.Builder) (Proxy @TextBuilder)
 
   describe "Data.Text.Encoding.StrictBuilder" do
     Main.Conversions.StrictBuilder.spec
diff --git a/src/hspec/Main/Conversions/StrictBuilder.hs b/src/hspec/Main/Conversions/StrictBuilder.hs
--- a/src/hspec/Main/Conversions/StrictBuilder.hs
+++ b/src/hspec/Main/Conversions/StrictBuilder.hs
@@ -15,7 +15,7 @@
 import Prelude
 
 spec :: Spec
-spec = allIs (Proxy @TextBuilder) (Proxy @TextEncoding.StrictBuilder)
+spec = allUptoIs (Proxy @TextBuilder) (Proxy @TextEncoding.StrictBuilder)
 
 instance Eq TextEncoding.StrictBuilder where
   a == b =
diff --git a/src/hspec/Main/Conversions/StrictTextBuilder.hs b/src/hspec/Main/Conversions/StrictTextBuilder.hs
--- a/src/hspec/Main/Conversions/StrictTextBuilder.hs
+++ b/src/hspec/Main/Conversions/StrictTextBuilder.hs
@@ -15,7 +15,7 @@
 import Prelude
 
 spec :: Spec
-spec = allIs (Proxy @TextBuilder) (Proxy @TextEncoding.StrictTextBuilder)
+spec = allUptoIs (Proxy @TextBuilder) (Proxy @TextEncoding.StrictTextBuilder)
 
 instance Eq TextEncoding.StrictTextBuilder where
   a == b =
diff --git a/src/hspec/Main/LawfulConversionsHspec.hs b/src/hspec/Main/LawfulConversionsHspec.hs
--- a/src/hspec/Main/LawfulConversionsHspec.hs
+++ b/src/hspec/Main/LawfulConversionsHspec.hs
@@ -25,8 +25,8 @@
   forM_ (LawfulConversions.isProperties a b) \(name, property) ->
     prop name property
 
-allIs :: (LawfulConversions.Is a b, Eq a, Eq b, Show a, Show b, Arbitrary a, Arbitrary b) => Proxy a -> Proxy b -> Spec
-allIs a b = do
+allUptoIs :: (LawfulConversions.Is a b, Eq a, Eq b, Show a, Show b, Arbitrary a, Arbitrary b) => Proxy a -> Proxy b -> Spec
+allUptoIs a b = do
   describe "Forward" do
     isSome a b
     isMany a b
@@ -36,3 +36,8 @@
     isSome b a
     isMany b a
     is b a
+
+allUptoIsMany :: (LawfulConversions.IsMany a b, Eq a, Eq b, Show a, Show b, Arbitrary a, Arbitrary b) => Proxy a -> Proxy b -> Spec
+allUptoIsMany a b = do
+  isSome a b
+  isMany a b
diff --git a/src/library/TextBuilderLawfulConversions.hs b/src/library/TextBuilderLawfulConversions.hs
--- a/src/library/TextBuilderLawfulConversions.hs
+++ b/src/library/TextBuilderLawfulConversions.hs
@@ -22,3 +22,4 @@
 import TextBuilderLawfulConversions.StrictBuilder ()
 import TextBuilderLawfulConversions.StrictText ()
 import TextBuilderLawfulConversions.StrictTextBuilder ()
+import TextBuilderLawfulConversions.String ()
diff --git a/src/library/TextBuilderLawfulConversions/String.hs b/src/library/TextBuilderLawfulConversions/String.hs
new file mode 100644
--- /dev/null
+++ b/src/library/TextBuilderLawfulConversions/String.hs
@@ -0,0 +1,16 @@
+{-# OPTIONS_GHC -Wno-orphans #-}
+
+module TextBuilderLawfulConversions.String where
+
+import Data.Function
+import Data.Functor
+import Data.String
+import LawfulConversions
+import TextBuilder
+
+instance IsSome String TextBuilder where
+  to = toString
+  maybeFrom = fmap text . maybeFrom
+
+instance IsMany String TextBuilder where
+  from = string
diff --git a/text-builder-lawful-conversions.cabal b/text-builder-lawful-conversions.cabal
--- a/text-builder-lawful-conversions.cabal
+++ b/text-builder-lawful-conversions.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: text-builder-lawful-conversions
-version: 0.1.2
+version: 0.1.3
 category: Text, Builders, Conversions
 synopsis: Orphan instances of "lawful-conversions" for "text-builder"
 homepage: https://github.com/nikita-volkov/text-builder-lawful-conversions
@@ -85,6 +85,7 @@
     TextBuilderLawfulConversions.StrictBuilder
     TextBuilderLawfulConversions.StrictText
     TextBuilderLawfulConversions.StrictTextBuilder
+    TextBuilderLawfulConversions.String
 
   build-depends:
     base >=4.13 && <5,