diff --git a/spec/std/openssl/digest_io_spec.cr b/spec/std/openssl/digest_io_spec.cr
index 6b3fb3a450d8..e57035a96365 100644
--- a/spec/std/openssl/digest_io_spec.cr
+++ b/spec/std/openssl/digest_io_spec.cr
@@ -31,7 +31,7 @@ describe OpenSSL::DigestIO do
     base_io = IO::Memory.new("foo")
     base_digest = OpenSSL::Digest.new("SHA256")
     empty_digest = OpenSSL::Digest.new("SHA256").digest
-    io = OpenSSL::DigestIO.new(base_io, base_digest, digest_on_read: false)
+    io = OpenSSL::DigestIO.new(base_io, base_digest, OpenSSL::DigestIO::DigestMode::Write)
     slice = Bytes.new(256)
     io.read(slice).should eq(3)
     slice[0, 3].should eq("foo".to_slice)
@@ -41,7 +41,7 @@ describe OpenSSL::DigestIO do
   it "calculates digest from writing" do
     base_io = IO::Memory.new
     base_digest = OpenSSL::Digest.new("SHA256")
-    io = OpenSSL::DigestIO.new(base_io, base_digest)
+    io = OpenSSL::DigestIO.new(base_io, base_digest, OpenSSL::DigestIO::DigestMode::Write)
     io.write("foo".to_slice)
 
     base_io.to_slice[0, 3].should eq("foo".to_slice)
@@ -51,7 +51,7 @@ describe OpenSSL::DigestIO do
   it "calculates digest from writing a string" do
     base_io = IO::Memory.new
     base_digest = OpenSSL::Digest.new("SHA256")
-    io = OpenSSL::DigestIO.new(base_io, base_digest)
+    io = OpenSSL::DigestIO.new(base_io, base_digest, OpenSSL::DigestIO::DigestMode::Write)
     io.print("foo")
 
     base_io.to_slice[0, 3].should eq("foo".to_slice)
@@ -61,7 +61,7 @@ describe OpenSSL::DigestIO do
   it "calculates digest from multiple writes" do
     base_io = IO::Memory.new
     base_digest = OpenSSL::Digest.new("SHA256")
-    io = OpenSSL::DigestIO.new(base_io, base_digest)
+    io = OpenSSL::DigestIO.new(base_io, base_digest, OpenSSL::DigestIO::DigestMode::Write)
     io.write("fo".to_slice)
     io.write("o".to_slice)
     base_io.to_slice[0, 3].should eq("foo".to_slice)
@@ -73,7 +73,7 @@ describe OpenSSL::DigestIO do
     base_io = IO::Memory.new
     base_digest = OpenSSL::Digest.new("SHA256")
     empty_digest = OpenSSL::Digest.new("SHA256").digest
-    io = OpenSSL::DigestIO.new(base_io, base_digest, digest_on_write: false)
+    io = OpenSSL::DigestIO.new(base_io, base_digest, OpenSSL::DigestIO::DigestMode::Read)
     io.write("foo".to_slice)
 
     base_io.to_slice[0, 3].should eq("foo".to_slice)
diff --git a/src/openssl/digest/digest_io.cr b/src/openssl/digest/digest_io.cr
index e464581aa7eb..9eb6bd216feb 100644
--- a/src/openssl/digest/digest_io.cr
+++ b/src/openssl/digest/digest_io.cr
@@ -1,6 +1,6 @@
 require "./digest_base"
 
-# Wraps an IO by calculating a specified digest on read and/or write operations
+# Wraps an IO by calculating a specified digest on read or write operations
 #
 # ### Example
 #
@@ -20,30 +20,33 @@ module OpenSSL
 
     getter io : IO
     getter digest_algorithm : OpenSSL::Digest
-    getter digest_on_read : Bool
-    getter digest_on_write : Bool
+    getter mode : DigestMode
 
     delegate close, closed?, flush, peek, tty?, rewind, to: @io
-    delegate digest, to: @digest_algorithm
     delegate digest, hexdigest, base64digest, to: @digest_algorithm
 
-    def initialize(@io : IO, @digest_algorithm : OpenSSL::Digest, *, @digest_on_read = true, @digest_on_write = true)
+    enum DigestMode
+      Read,
+      Write
     end
 
-    def initialize(@io : IO, algorithm : String, *, @digest_on_read = true, @digest_on_write = true)
+    def initialize(@io : IO, @digest_algorithm : OpenSSL::Digest, @mode = DigestMode::Read)
+    end
+
+    def initialize(@io : IO, algorithm : String, @mode = DigestMode::Read)
       @digest_algorithm = OpenSSL::Digest.new(algorithm)
     end
 
     def read(slice : Bytes)
       read_bytes = io.read(slice)
-      if @digest_on_read
+      if @mode == DigestMode::Read
         digest_algorithm.update(slice[0, read_bytes])
       end
       read_bytes
     end
 
     def write(slice : Bytes)
-      if @digest_on_write
+      if @mode == DigestMode::Write
         digest_algorithm.update(slice)
       end
       io.write(slice)