diff --git a/lib/bashly/extensions/array.rb b/lib/bashly/extensions/array.rb
index 92e0dfb2..739d6826 100644
--- a/lib/bashly/extensions/array.rb
+++ b/lib/bashly/extensions/array.rb
@@ -3,7 +3,17 @@ def indent(offset)
     return self unless offset.positive?
 
     indentation = ' ' * offset
-    map { |line| "#{indentation}#{line}" }
+    heredoc_marker = nil
+
+    map do |line|
+      if heredoc_marker
+        heredoc_marker = nil if /^#{heredoc_marker}\n?$/.match?(line)
+        line
+      else
+        heredoc_marker = $1 if line =~ /<<-?(\w+)\n?$/
+        "#{indentation}#{line}"
+      end
+    end
   end
 
   def nonuniq
diff --git a/spec/approvals/fixtures/heredoc b/spec/approvals/fixtures/heredoc
new file mode 100644
index 00000000..217a6115
--- /dev/null
+++ b/spec/approvals/fixtures/heredoc
@@ -0,0 +1,16 @@
++ bundle exec bashly generate
+creating user files in src
+skipped src/root_command.sh (exists)
+created ./cli
+run ./cli --help to test your bash script
++ ./cli
+unindented
+multiline
+heredoc text
+also unindented
+  1 indentation
+    2 indentations
+      3 indentations
+
+      3 indentations with empty line above
+also unindented
diff --git a/spec/bashly/extensions/array_spec.rb b/spec/bashly/extensions/array_spec.rb
index abd8a98c..0d27246d 100644
--- a/spec/bashly/extensions/array_spec.rb
+++ b/spec/bashly/extensions/array_spec.rb
@@ -11,6 +11,40 @@
         expect(subject.indent(0)).to eq subject
       end
     end
+
+    context 'when the string contains heredoc block' do
+      subject do
+        result = <<~SUBJECT
+          function() {
+            cat <<-SOME_EOF_MARKER
+          not-indented
+            indented-once
+              indented-twice
+          SOME_EOF_MARKER
+          } # indented with function() start
+        SUBJECT
+
+        result.lines
+      end
+
+      let(:expected) do
+        result = <<~SUBJECT
+            function() {
+              cat <<-SOME_EOF_MARKER
+          not-indented
+            indented-once
+              indented-twice
+          SOME_EOF_MARKER
+            } # indented with function() start
+        SUBJECT
+
+        result.lines
+      end
+
+      it 'does not indent it but indents everything else' do
+        expect(subject.indent 2).to eq expected
+      end
+    end
   end
 
   describe '#nonuniq' do
diff --git a/spec/fixtures/workspaces/heredoc/.gitignore b/spec/fixtures/workspaces/heredoc/.gitignore
new file mode 100644
index 00000000..573c0c4f
--- /dev/null
+++ b/spec/fixtures/workspaces/heredoc/.gitignore
@@ -0,0 +1 @@
+cli
diff --git a/spec/fixtures/workspaces/heredoc/README.md b/spec/fixtures/workspaces/heredoc/README.md
new file mode 100644
index 00000000..7575db38
--- /dev/null
+++ b/spec/fixtures/workspaces/heredoc/README.md
@@ -0,0 +1 @@
+This fixture tests that heredoc blocks are kept unindented
\ No newline at end of file
diff --git a/spec/fixtures/workspaces/heredoc/src/bashly.yml b/spec/fixtures/workspaces/heredoc/src/bashly.yml
new file mode 100644
index 00000000..7d8d192f
--- /dev/null
+++ b/spec/fixtures/workspaces/heredoc/src/bashly.yml
@@ -0,0 +1,3 @@
+name: cli
+help: Sample application to test heredoc
+version: 0.1.0
diff --git a/spec/fixtures/workspaces/heredoc/src/root_command.sh b/spec/fixtures/workspaces/heredoc/src/root_command.sh
new file mode 100644
index 00000000..9c8db660
--- /dev/null
+++ b/spec/fixtures/workspaces/heredoc/src/root_command.sh
@@ -0,0 +1,18 @@
+echo unindented
+
+cat <<-FIRST_BLOCK
+multiline
+heredoc text
+FIRST_BLOCK
+
+echo also unindented
+
+cat <<-SECOND_BLOCK
+  1 indentation
+    2 indentations
+      3 indentations
+
+      3 indentations with empty line above
+SECOND_BLOCK
+
+echo also unindented
diff --git a/spec/fixtures/workspaces/heredoc/test.sh b/spec/fixtures/workspaces/heredoc/test.sh
new file mode 100644
index 00000000..fade5ea5
--- /dev/null
+++ b/spec/fixtures/workspaces/heredoc/test.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+set -x
+
+bundle exec bashly generate
+
+./cli
+