diff --git a/src/main/java/org/cactoos/text/Abbreviated.java b/src/main/java/org/cactoos/text/Abbreviated.java
index 536b4a3f0..02f6997e1 100644
--- a/src/main/java/org/cactoos/text/Abbreviated.java
+++ b/src/main/java/org/cactoos/text/Abbreviated.java
@@ -53,9 +53,9 @@ public final class Abbreviated extends TextEnvelope {
      *
      * <p> By default, the max line width is 80 characters.
      *
-     * @param text The Text
+     * @param text The CharSequence
      */
-    public Abbreviated(final String text) {
+    public Abbreviated(final CharSequence text) {
         this(new TextOf(text));
     }
 
diff --git a/src/main/java/org/cactoos/text/Base64Decoded.java b/src/main/java/org/cactoos/text/Base64Decoded.java
index 5f1f61f46..e34ed6c2a 100644
--- a/src/main/java/org/cactoos/text/Base64Decoded.java
+++ b/src/main/java/org/cactoos/text/Base64Decoded.java
@@ -37,9 +37,9 @@ public final class Base64Decoded extends TextEnvelope {
     /**
      * Ctor.
      *
-     * @param input The String
+     * @param input The CharSequence
      */
-    public Base64Decoded(final String input) {
+    public Base64Decoded(final CharSequence input) {
         this(new TextOf(input));
     }
 
diff --git a/src/main/java/org/cactoos/text/Base64Encoded.java b/src/main/java/org/cactoos/text/Base64Encoded.java
index 05852b6d3..84ac8741a 100644
--- a/src/main/java/org/cactoos/text/Base64Encoded.java
+++ b/src/main/java/org/cactoos/text/Base64Encoded.java
@@ -38,9 +38,9 @@ public final class Base64Encoded extends TextEnvelope {
     /**
      * Ctor.
      *
-     * @param input The String
+     * @param input The CharSequence
      */
-    public Base64Encoded(final String input) {
+    public Base64Encoded(final CharSequence input) {
         this(new TextOf(input));
     }
 
diff --git a/src/main/java/org/cactoos/text/Capitalized.java b/src/main/java/org/cactoos/text/Capitalized.java
index 00042e832..dcadd6cf6 100644
--- a/src/main/java/org/cactoos/text/Capitalized.java
+++ b/src/main/java/org/cactoos/text/Capitalized.java
@@ -42,7 +42,7 @@ public final class Capitalized extends TextEnvelope {
      *
      * @param text The text
      */
-    public Capitalized(final String text) {
+    public Capitalized(final CharSequence text) {
         this(new TextOf(text));
     }
 
diff --git a/src/main/java/org/cactoos/text/Concatenated.java b/src/main/java/org/cactoos/text/Concatenated.java
index 562547d53..f0ceab96b 100644
--- a/src/main/java/org/cactoos/text/Concatenated.java
+++ b/src/main/java/org/cactoos/text/Concatenated.java
@@ -46,9 +46,9 @@ public Concatenated(final Text... txts) {
 
     /**
      * Ctor.
-     * @param strs Strings to be concatenated
+     * @param strs CharSequences to be concatenated
      */
-    public Concatenated(final String... strs) {
+    public Concatenated(final CharSequence... strs) {
         this(
             new Mapped<>(
                 TextOf::new,
diff --git a/src/main/java/org/cactoos/text/Contains.java b/src/main/java/org/cactoos/text/Contains.java
index 92a36a5bb..a096a1f76 100644
--- a/src/main/java/org/cactoos/text/Contains.java
+++ b/src/main/java/org/cactoos/text/Contains.java
@@ -48,7 +48,7 @@ public final class Contains implements Scalar<Boolean> {
      * @param origin The origin
      * @param other The other
      */
-    public Contains(final String origin, final String other) {
+    public Contains(final CharSequence origin, final CharSequence other) {
         this(new TextOf(origin), new TextOf(other));
     }
 
@@ -57,7 +57,7 @@ public Contains(final String origin, final String other) {
      * @param origin The origin
      * @param other The other
      */
-    public Contains(final String origin, final Text other) {
+    public Contains(final CharSequence origin, final Text other) {
         this(new TextOf(origin), other);
     }
 
diff --git a/src/main/java/org/cactoos/text/EndsWith.java b/src/main/java/org/cactoos/text/EndsWith.java
index a9da4705a..1b3376c5b 100644
--- a/src/main/java/org/cactoos/text/EndsWith.java
+++ b/src/main/java/org/cactoos/text/EndsWith.java
@@ -48,7 +48,7 @@ public final class EndsWith implements Scalar<Boolean> {
      * @param origin The origin
      * @param suffix The suffix
      */
-    public EndsWith(final Text origin, final String suffix) {
+    public EndsWith(final Text origin, final CharSequence suffix) {
         this(origin, new TextOf(suffix));
     }
 
diff --git a/src/main/java/org/cactoos/text/FormattedText.java b/src/main/java/org/cactoos/text/FormattedText.java
index 293aa6244..64be149d5 100644
--- a/src/main/java/org/cactoos/text/FormattedText.java
+++ b/src/main/java/org/cactoos/text/FormattedText.java
@@ -94,7 +94,7 @@ public FormattedText(
      * @param ptn Pattern
      * @param arguments Arguments
      */
-    public FormattedText(final String ptn, final Collection<Object> arguments) {
+    public FormattedText(final CharSequence ptn, final Collection<Object> arguments) {
         this(ptn, Locale.getDefault(Locale.Category.FORMAT), arguments);
     }
 
@@ -116,7 +116,7 @@ public FormattedText(final Text ptn, final Collection<Object> arguments) {
      * @param arguments Arguments
      */
     public FormattedText(
-        final String ptn,
+        final CharSequence ptn,
         final Locale locale,
         final Collection<Object> arguments
     ) {
diff --git a/src/main/java/org/cactoos/text/Joined.java b/src/main/java/org/cactoos/text/Joined.java
index db9744981..0cebaca5e 100644
--- a/src/main/java/org/cactoos/text/Joined.java
+++ b/src/main/java/org/cactoos/text/Joined.java
@@ -42,7 +42,7 @@ public final class Joined extends TextEnvelope {
      * @param delimit Delimit among strings
      * @param strs Strings to be joined
      */
-    public Joined(final String delimit, final String... strs) {
+    public Joined(final CharSequence delimit, final CharSequence... strs) {
         this(delimit, new IterableOf<>(strs));
     }
 
@@ -51,7 +51,7 @@ public Joined(final String delimit, final String... strs) {
      * @param delimit Delimit among strings
      * @param strs Strings to be joined
      */
-    public Joined(final String delimit, final Iterable<String> strs) {
+    public Joined(final CharSequence delimit, final Iterable<? extends CharSequence> strs) {
         this(
             new TextOf(delimit),
             new Mapped<>(TextOf::new, strs)
diff --git a/src/main/java/org/cactoos/text/Lowered.java b/src/main/java/org/cactoos/text/Lowered.java
index 3042faa07..47562a0fb 100644
--- a/src/main/java/org/cactoos/text/Lowered.java
+++ b/src/main/java/org/cactoos/text/Lowered.java
@@ -39,7 +39,7 @@ public final class Lowered extends TextEnvelope {
      * Ctor.
      * @param text The text
      */
-    public Lowered(final String text) {
+    public Lowered(final CharSequence text) {
         this(new TextOf(text));
     }
 
diff --git a/src/main/java/org/cactoos/text/Mapped.java b/src/main/java/org/cactoos/text/Mapped.java
index 9dbfc71a2..f4064c167 100644
--- a/src/main/java/org/cactoos/text/Mapped.java
+++ b/src/main/java/org/cactoos/text/Mapped.java
@@ -39,7 +39,7 @@ public final class Mapped extends TextEnvelope {
      * @param fnc Function to apply
      * @param txt Original text
      */
-    public Mapped(final Func<String, String> fnc, final Text txt) {
+    public Mapped(final Func<String, ? extends CharSequence> fnc, final Text txt) {
         super(new TextOf(() -> fnc.apply(txt.asString())));
     }
 
diff --git a/src/main/java/org/cactoos/text/Normalized.java b/src/main/java/org/cactoos/text/Normalized.java
index f86754ce8..06c7fd484 100644
--- a/src/main/java/org/cactoos/text/Normalized.java
+++ b/src/main/java/org/cactoos/text/Normalized.java
@@ -37,7 +37,7 @@ public final class Normalized extends TextEnvelope {
      * Ctor.
      * @param text A Text
      */
-    public Normalized(final String text) {
+    public Normalized(final CharSequence text) {
         this(new TextOf(text));
     }
 
@@ -55,4 +55,3 @@ public Normalized(final Text text) {
         );
     }
 }
-
diff --git a/src/main/java/org/cactoos/text/PrefixOf.java b/src/main/java/org/cactoos/text/PrefixOf.java
index 33ed6e6c2..643dd2235 100644
--- a/src/main/java/org/cactoos/text/PrefixOf.java
+++ b/src/main/java/org/cactoos/text/PrefixOf.java
@@ -24,8 +24,6 @@
 package org.cactoos.text;
 
 import org.cactoos.Text;
-import org.cactoos.func.FuncOf;
-import org.cactoos.scalar.Constant;
 import org.cactoos.scalar.ScalarOf;
 import org.cactoos.scalar.Ternary;
 
@@ -40,10 +38,10 @@ public final class PrefixOf extends TextEnvelope {
 
     /**
      * Ctor.
-     * @param text Text representing the text value
-     * @param boundary String to which text will be split
+     * @param text CharSequence representing the text value
+     * @param boundary CharSequence to which text will be split
      */
-    public PrefixOf(final String text, final String boundary) {
+    public PrefixOf(final CharSequence text, final CharSequence boundary) {
         this(new TextOf(text), boundary);
     }
 
@@ -52,13 +50,13 @@ public PrefixOf(final String text, final String boundary) {
      * @param text Text representing the text value
      * @param boundary String to which text will be split
      */
-    public PrefixOf(final Text text, final String boundary) {
+    public PrefixOf(final Text text, final CharSequence boundary) {
         super(
             new Flattened(
                 new Ternary<>(
                     new ScalarOf<>(() -> new Sticky(text)),
-                    (Text t) -> t.asString().indexOf(boundary) >= 0,
-                    t -> new Sub(t, 0, s -> s.indexOf(boundary)),
+                    (Text t) -> t.asString().contains(boundary.toString()),
+                    t -> new Sub(t, 0, s -> s.indexOf(boundary.toString())),
                     t -> t
                 )
             )
diff --git a/src/main/java/org/cactoos/text/Repeated.java b/src/main/java/org/cactoos/text/Repeated.java
index 515738c42..2dec6e3ea 100644
--- a/src/main/java/org/cactoos/text/Repeated.java
+++ b/src/main/java/org/cactoos/text/Repeated.java
@@ -39,7 +39,7 @@ public final class Repeated extends TextEnvelope {
      * @param text A String
      * @param count How many times repeat the Text
      */
-    public Repeated(final String text, final int count) {
+    public Repeated(final CharSequence text, final int count) {
         this(new TextOf(text), count);
     }
 
diff --git a/src/main/java/org/cactoos/text/Split.java b/src/main/java/org/cactoos/text/Split.java
index 2ed80241b..6a5637f07 100644
--- a/src/main/java/org/cactoos/text/Split.java
+++ b/src/main/java/org/cactoos/text/Split.java
@@ -44,7 +44,7 @@ public final class Split extends IterableEnvelope<Text> {
      * @param rgx The regex
      * @see String#split(String)
      */
-    public Split(final String text, final String rgx) {
+    public Split(final CharSequence text, final CharSequence rgx) {
         this(new TextOf(text), new TextOf(rgx));
     }
 
@@ -56,7 +56,7 @@ public Split(final String text, final String rgx) {
      * @param lmt The limit
      * @see String#split(String, int)
      */
-    public Split(final String text, final String rgx, final int lmt) {
+    public Split(final CharSequence text, final CharSequence rgx, final int lmt) {
         this(new TextOf(text), new TextOf(rgx), lmt);
     }
 
@@ -66,7 +66,7 @@ public Split(final String text, final String rgx, final int lmt) {
      * @param rgx The regex
      * @see String#split(String)
      */
-    public Split(final String text, final Text rgx) {
+    public Split(final CharSequence text, final Text rgx) {
         this(new TextOf(text), rgx);
     }
 
@@ -87,7 +87,7 @@ public Split(final String text, final Text rgx, final int lmt) {
      * @param rgx The regex
      * @see String#split(String)
      */
-    public Split(final Text text, final String rgx) {
+    public Split(final Text text, final CharSequence rgx) {
         this(text, new TextOf(rgx));
     }
 
diff --git a/src/main/java/org/cactoos/text/StartsWith.java b/src/main/java/org/cactoos/text/StartsWith.java
index 4ed2022a8..822aaab88 100644
--- a/src/main/java/org/cactoos/text/StartsWith.java
+++ b/src/main/java/org/cactoos/text/StartsWith.java
@@ -62,7 +62,7 @@ public StartsWith(final Text text, final Text prefix) {
      * @param text The text
      * @param prefix The prefix
      */
-    public StartsWith(final String text, final String prefix) {
+    public StartsWith(final CharSequence text, final CharSequence prefix) {
         this(new TextOf(text), new TextOf(prefix));
     }
 
diff --git a/src/main/java/org/cactoos/text/Sub.java b/src/main/java/org/cactoos/text/Sub.java
index ae708aa25..5683547e4 100644
--- a/src/main/java/org/cactoos/text/Sub.java
+++ b/src/main/java/org/cactoos/text/Sub.java
@@ -42,7 +42,7 @@ public final class Sub extends TextEnvelope {
      * @param text The String
      * @param strt Start position in the text
      */
-    public Sub(final String text, final int strt) {
+    public Sub(final CharSequence text, final int strt) {
         this(new TextOf(text), strt);
     }
 
@@ -52,7 +52,7 @@ public Sub(final String text, final int strt) {
      * @param strt Start position in the text
      * @param finish End position in the text
      */
-    public Sub(final String text, final int strt, final int finish) {
+    public Sub(final CharSequence text, final int strt, final int finish) {
         this(new TextOf(text), strt, finish);
     }
 
diff --git a/src/main/java/org/cactoos/text/SuffixOf.java b/src/main/java/org/cactoos/text/SuffixOf.java
index 42acaec47..dae8954a3 100644
--- a/src/main/java/org/cactoos/text/SuffixOf.java
+++ b/src/main/java/org/cactoos/text/SuffixOf.java
@@ -24,6 +24,7 @@
 package org.cactoos.text;
 
 import org.cactoos.Text;
+import org.cactoos.scalar.LengthOf;
 import org.cactoos.scalar.ScalarOf;
 import org.cactoos.scalar.Ternary;
 
@@ -41,7 +42,7 @@ public final class SuffixOf extends TextEnvelope {
      * @param text Text representing the text value
      * @param boundary String after which text will be split
      */
-    public SuffixOf(final String text, final String boundary) {
+    public SuffixOf(final CharSequence text, final CharSequence boundary) {
         this(new TextOf(text), boundary);
     }
 
@@ -50,15 +51,16 @@ public SuffixOf(final String text, final String boundary) {
      * @param text Text representing the text value
      * @param boundary String after which text will be split
      */
-    public SuffixOf(final Text text, final String boundary) {
+    public SuffixOf(final Text text, final CharSequence boundary) {
         super(
             new Flattened(
                 new Ternary<>(
                     new ScalarOf<>(() -> new Sticky(text)),
-                    (Text t) -> t.asString().indexOf(boundary) >= 0,
+                    (Text t) -> t.asString().contains(boundary.toString()),
                     t -> new Sub(
                         t,
-                        s -> s.indexOf(boundary) + boundary.length()
+                        s -> s.indexOf(boundary.toString())
+                            + boundary.length()
                     ),
                     t -> new TextOf("")
                 )
diff --git a/src/main/java/org/cactoos/text/TextOf.java b/src/main/java/org/cactoos/text/TextOf.java
index 42ed8209c..4e1a52865 100644
--- a/src/main/java/org/cactoos/text/TextOf.java
+++ b/src/main/java/org/cactoos/text/TextOf.java
@@ -169,20 +169,20 @@ public TextOf(final Reader rdr, final int max, final Charset cset) {
     /**
      * Ctor.
      *
-     * @param builder The String builder
+     * @param str The CharSequence
      */
-    public TextOf(final CharSequence builder) {
-        this(new BytesOf(builder));
+    public TextOf(final CharSequence str) {
+        this(new BytesOf(str));
     }
 
     /**
      * Ctor.
      *
-     * @param builder The String builder
+     * @param str The CharSequence
      * @param cset The Charset
      */
-    public TextOf(final CharSequence builder, final Charset cset) {
-        this(new BytesOf(builder, cset), cset);
+    public TextOf(final CharSequence str, final Charset cset) {
+        this(new BytesOf(str, cset), cset);
     }
 
     /**
@@ -368,7 +368,7 @@ public TextOf(final InputStream input) {
      *
      * @param scalar The Scalar of String
      */
-    public TextOf(final Scalar<String> scalar) {
+    public TextOf(final Scalar<? extends CharSequence> scalar) {
         this(new TextOfScalar(scalar));
     }
 
diff --git a/src/main/java/org/cactoos/text/TextOfScalar.java b/src/main/java/org/cactoos/text/TextOfScalar.java
index 42d9ed31c..12a4a6e22 100644
--- a/src/main/java/org/cactoos/text/TextOfScalar.java
+++ b/src/main/java/org/cactoos/text/TextOfScalar.java
@@ -39,22 +39,22 @@
 public final class TextOfScalar implements Text {
 
     /**
-     * String value of the envelope.
+     * Value of the envelope.
      */
-    private final Scalar<String> origin;
+    private final Scalar<? extends CharSequence> origin;
 
     /**
      * Ctor.
      *
-     * @param scalar The Scalar of String
+     * @param scalar The scalar of CharSequence
      */
-    public TextOfScalar(final Scalar<String> scalar) {
+    public TextOfScalar(final Scalar<? extends CharSequence> scalar) {
         this.origin = scalar;
     }
 
     @Override
     public String asString() throws Exception {
-        return this.origin.value();
+        return this.origin.value().toString();
     }
 
     @Override
diff --git a/src/main/java/org/cactoos/text/Upper.java b/src/main/java/org/cactoos/text/Upper.java
index 4615ae274..5443d73c7 100644
--- a/src/main/java/org/cactoos/text/Upper.java
+++ b/src/main/java/org/cactoos/text/Upper.java
@@ -40,7 +40,7 @@ public final class Upper extends TextEnvelope {
      * Ctor.
      * @param text The text
      */
-    public Upper(final String text) {
+    public Upper(final CharSequence text) {
         this(new TextOf(text));
     }