diff --git a/doc/string/rjust.rdoc b/doc/string/rjust.rdoc
index 24e7bf31595653..864cfcce7a0ec0 100644
--- a/doc/string/rjust.rdoc
+++ b/doc/string/rjust.rdoc
@@ -1,7 +1,7 @@
 Returns a right-justified copy of +self+.
 
-If integer argument +size+ is greater than the size (in characters) of +self+,
-returns a new string of length +size+ that is a copy of +self+,
+If integer argument +width+ is greater than the size (in characters) of +self+,
+returns a new string of length +width+ that is a copy of +self+,
 right justified and padded on the left with +pad_string+:
 
   'hello'.rjust(10)       # => "     hello"
@@ -10,7 +10,9 @@ right justified and padded on the left with +pad_string+:
   'тест'.rjust(10)        # => "      тест"
   'こんにちは'.rjust(10)    # => "     こんにちは"
 
-If +size+ is not greater than the size of +self+, returns a copy of +self+:
+If <tt>width <= self.size</tt>, returns a copy of +self+:
 
   'hello'.rjust(5, 'ab')  # => "hello"
   'hello'.rjust(1, 'ab')  # => "hello"
+
+Related: see {Converting to New String}[rdoc-ref:String@Converting+to+New+String].
diff --git a/doc/strscan/strscan.md b/doc/strscan/strscan.md
index aa7bd8ba847d82..c0bf5413623b07 100644
--- a/doc/strscan/strscan.md
+++ b/doc/strscan/strscan.md
@@ -204,7 +204,7 @@ put_situation(scanner)
 
 ## Target Substring
 
-The target substring is the the part of the [stored string][1]
+The target substring is the part of the [stored string][1]
 that extends from the current [byte position][2] to the end of the stored string;
 it is always either:
 
diff --git a/error.c b/error.c
index 2f24929d44ea91..abf50b696aefa6 100644
--- a/error.c
+++ b/error.c
@@ -1686,7 +1686,7 @@ check_order_keyword(VALUE opt)
  *   - If the value of keyword +order+ is +:top+ (the default),
  *     lists the error message and the innermost backtrace entry first.
  *   - If the value of keyword +order+ is +:bottom+,
- *     lists the error message the the innermost entry last.
+ *     lists the error message the innermost entry last.
  *
  * Example:
  *
diff --git a/internal/io.h b/internal/io.h
index e6a741ee71faee..b81774e0a715df 100644
--- a/internal/io.h
+++ b/internal/io.h
@@ -132,7 +132,7 @@ struct rb_io {
     struct rb_execution_context_struct *closing_ec;
     VALUE wakeup_mutex;
 
-    // The fork generation of the the blocking operations list.
+    // The fork generation of the blocking operations list.
     rb_serial_t fork_generation;
 };
 
diff --git a/string.c b/string.c
index f797dab6516f8d..fab1509bac0ead 100644
--- a/string.c
+++ b/string.c
@@ -11177,12 +11177,10 @@ rb_str_ljust(int argc, VALUE *argv, VALUE str)
 
 /*
  *  call-seq:
- *    rjust(size, pad_string = ' ') -> new_string
+ *    rjust(width, pad_string = ' ') -> new_string
  *
  *  :include: doc/string/rjust.rdoc
  *
- *  Related: String#ljust, String#center.
- *
  */
 
 static VALUE
diff --git a/zjit/src/asm/arm64/mod.rs b/zjit/src/asm/arm64/mod.rs
index beb5a4b7bd61c7..ffb83cf16abd03 100644
--- a/zjit/src/asm/arm64/mod.rs
+++ b/zjit/src/asm/arm64/mod.rs
@@ -18,7 +18,7 @@ pub use arg::*;
 pub use opnd::*;
 
 /// The extend type for register operands in extended register instructions.
-/// It's the reuslt size is determined by the the destination register and
+/// It's the result size is determined by the destination register and
 /// the source size interpreted using the last letter.
 #[derive(Clone, Copy)]
 pub enum ExtendType {