1 files changed, 3 insertions, 3 deletions
diff --git a/spec/ruby/optional/capi/encoding_spec.rb b/spec/ruby/optional/capi/encoding_spec.rb
index 857e421ddb..b74a360760 100644
--- a/spec/ruby/optional/capi/encoding_spec.rb
+++ b/spec/ruby/optional/capi/encoding_spec.rb
@@ -312,7 +312,7 @@ describe "C-API Encoding function" do
     end
 
     it "sets the encoding of a Regexp to that of the second argument" do
-      @s.rb_enc_copy(/regexp/, @obj).encoding.should == Encoding::US_ASCII
+      @s.rb_enc_copy(/regexp/.dup, @obj).encoding.should == Encoding::US_ASCII
     end
   end
 
@@ -363,7 +363,7 @@ describe "C-API Encoding function" do
     end
 
     it "sets the encoding of a Regexp to the encoding" do
-      @s.rb_enc_associate(/regexp/, "BINARY").encoding.should == Encoding::BINARY
+      @s.rb_enc_associate(/regexp/.dup, "BINARY").encoding.should == Encoding::BINARY
     end
 
     it "sets the encoding of a String to a default when the encoding is NULL" do
@@ -380,7 +380,7 @@ describe "C-API Encoding function" do
 
     it "sets the encoding of a Regexp to the encoding" do
       index = @s.rb_enc_find_index("UTF-8")
-      enc = @s.rb_enc_associate_index(/regexp/, index).encoding
+      enc = @s.rb_enc_associate_index(/regexp/.dup, index).encoding
       enc.should == Encoding::UTF_8
     end