diff --git a/core/src/main/java/org/jruby/RubyString.java b/core/src/main/java/org/jruby/RubyString.java
index bf311e6a16f..b1d91b0a151 100644
--- a/core/src/main/java/org/jruby/RubyString.java
+++ b/core/src/main/java/org/jruby/RubyString.java
@@ -7191,7 +7191,7 @@ public static IRubyObject includeRange(ThreadContext context, RubyString _beg, R
                         (e = eByteList.get(0)) < 128 &&
                         (v = vByteList.get(0)) < 128) {
                     if (b <= v && v < e) return context.tru;
-                    if (!exclusive && v == e) return context.tru;
+                    if (!exclusive && b <= v && v == e) return context.tru;
                     return context.fals;
                 }
             }
diff --git a/test/mri/ruby/test_range.rb b/test/mri/ruby/test_range.rb
index ff17dca69ee..7f097903d14 100644
--- a/test/mri/ruby/test_range.rb
+++ b/test/mri/ruby/test_range.rb
@@ -1034,6 +1034,11 @@ def test_include
     assert_include("a"..."z", "y")
     assert_not_include("a"..."z", "z")
     assert_not_include("a".."z", "cc")
+    assert_not_include("z".."a", "a")
+    assert_not_include("z".."a", "z")
+    assert_not_include("z".."a", "m")
+    assert_include("a".."a", "a")
+    assert_not_include("a"..."a", "a")
     assert_raise(TypeError) {("a"..).include?("c")}
     assert_raise(TypeError) {("a"..).include?("5")}