diff --git a/test/error_highlight/test_error_highlight.rb b/test/error_highlight/test_error_highlight.rb
index 9af530b69f6069..de6782b914d772 100644
--- a/test/error_highlight/test_error_highlight.rb
+++ b/test/error_highlight/test_error_highlight.rb
@@ -1239,7 +1239,7 @@ def custom_formatter.message_for(spot)
     assert_error_message(NoMethodError, <<~END) do
 undefined method `time' for #{ ONE_RECV_MESSAGE }
 
-{:first_lineno=>#{ __LINE__ + 3 }, :first_column=>7, :last_lineno=>#{ __LINE__ + 3 }, :last_column=>12, :snippet=>"      1.time {}\\n"}
+#{{ first_lineno: __LINE__ + 3, first_column: 7, last_lineno: __LINE__ + 3, last_column: 12, snippet: "      1.time {}\n" }.inspect}
     END
 
       1.time {}
diff --git a/test/rdoc/test_rdoc_ri_driver.rb b/test/rdoc/test_rdoc_ri_driver.rb
index 39e6e677596dbd..3263e6173ef001 100644
--- a/test/rdoc/test_rdoc_ri_driver.rb
+++ b/test/rdoc/test_rdoc_ri_driver.rb
@@ -54,10 +54,10 @@ def test_self_dump
       RDoc::RI::Driver.dump @store1.cache_path
     end
 
-    assert_match %r%:class_methods%,    out
-    assert_match %r%:modules%,          out
-    assert_match %r%:instance_methods%, out
-    assert_match %r%:ancestors%,        out
+    assert_match %r%:class_methods|class_methods:%,       out
+    assert_match %r%:modules|modules:%,                   out
+    assert_match %r%:instance_methods|instance_methods:%, out
+    assert_match %r%:ancestors|ancestors:%,               out
   end
 
   def test_add_also_in_empty
diff --git a/test/reline/test_reline.rb b/test/reline/test_reline.rb
index f2feab684da79b..9a68eb59f5444d 100644
--- a/test/reline/test_reline.rb
+++ b/test/reline/test_reline.rb
@@ -399,7 +399,7 @@ def test_read_eof_returns_input
       io.close_write
       io.read
     end
-    assert_include(out, '{:result=>"a"}')
+    assert_include(out, { result: "a" }.inspect)
   end
 
   def test_read_eof_returns_nil_if_empty
@@ -411,7 +411,7 @@ def test_read_eof_returns_nil_if_empty
       io.close_write
       io.read
     end
-    assert_include(out, '{:result=>nil}')
+    assert_include(out, { result: nil }.inspect)
   end
 
   def test_require_reline_should_not_trigger_winsize
diff --git a/test/rubygems/test_gem_dependency.rb b/test/rubygems/test_gem_dependency.rb
index 2a989a55513b99..a0bfee023936cb 100644
--- a/test/rubygems/test_gem_dependency.rb
+++ b/test/rubygems/test_gem_dependency.rb
@@ -22,7 +22,7 @@ def test_initialize_type_bad
       Gem::Dependency.new "monkey" => "1.0"
     end
 
-    assert_equal 'dependency name must be a String, was {"monkey"=>"1.0"}',
+    assert_equal "dependency name must be a String, was #{{ "monkey" => "1.0" }.inspect}",
                  e.message
   end
 
diff --git a/test/rubygems/test_require.rb b/test/rubygems/test_require.rb
index 30a4a477f9dfcc..8f156c08dab82e 100644
--- a/test/rubygems/test_require.rb
+++ b/test/rubygems/test_require.rb
@@ -689,11 +689,11 @@ def test_require_bundler
         _, err = capture_subprocess_io do
           system(*ruby_with_rubygems_in_load_path, "-w", "--disable=gems", "-C", dir, "main.rb")
         end
-        assert_match(/{:x=>1}\n{:y=>2}\n$/, err)
+        assert_match(/#{{ x: 1 }.inspect}\n#{{ y: 2 }.inspect}\n$/, err)
         _, err = capture_subprocess_io do
           system(*ruby_with_rubygems_in_load_path, "-w", "--enable=gems", "-C", dir, "main.rb")
         end
-        assert_match(/{:x=>1}\n{:y=>2}\n$/, err)
+        assert_match(/#{{ x: 1 }.inspect}\n#{{ y: 2 }.inspect}\n$/, err)
       end
     end
   end
diff --git a/test/test_pp.rb b/test/test_pp.rb
index 3d58d12b9225f2..f1db8245fc3582 100644
--- a/test/test_pp.rb
+++ b/test/test_pp.rb
@@ -138,8 +138,7 @@ def test_array
   def test_hash
     a = {}
     a[0] = a
-    assert_equal("{0=>{...}}\n", PP.pp(a, ''.dup))
-    assert_equal("#{a.inspect}\n", PP.pp(a, ''.dup))
+    assert_equal("{0 => {...}}\n", PP.pp(a, ''.dup))
   end
 
   S = Struct.new("S", :a, :b)
@@ -194,7 +193,7 @@ def test_share_nil
 
 class PPSingleLineTest < Test::Unit::TestCase
   def test_hash
-    assert_equal("{1=>1}", PP.singleline_pp({ 1 => 1}, ''.dup)) # [ruby-core:02699]
+    assert_equal("{1 => 1}", PP.singleline_pp({ 1 => 1}, ''.dup)) # [ruby-core:02699]
     assert_equal("[1#{', 1'*99}]", PP.singleline_pp([1]*100, ''.dup))
   end
 
@@ -261,7 +260,7 @@ class PPSymbolHash < PP
     def pp_hash_pair(k, v)
       case k
       when Symbol
-        text k.inspect.delete_prefix(":")
+        text k.inspect.delete_prefix(":").tr('"', "'")
         text ":"
         group(1) {
           breakable
@@ -276,7 +275,7 @@ def pp_hash_pair(k, v)
   def test_hash_override
     obj = {k: 1, "": :null, "0": :zero, 100 => :ten}
     assert_equal <<~EXPECT, PPSymbolHash.pp(obj, "".dup)
-    {k: 1, "": :null, "0": :zero, 100=>:ten}
+    {k: 1, '': :null, '0': :zero, 100 => :ten}
     EXPECT
   end
 end