diff --git a/ext/ffi_c/Function.c b/ext/ffi_c/Function.c
index 177180003..1bf751c27 100644
--- a/ext/ffi_c/Function.c
+++ b/ext/ffi_c/Function.c
@@ -721,7 +721,7 @@ invoke_callback(VALUE data)
                 param = rb_float_new(*(double *) parameters[i]);
                 break;
             case NATIVE_LONGDOUBLE:
-	      param = rbffi_longdouble_new(*(long double *) parameters[i]);
+                param = rbffi_longdouble_new(*(long double *) parameters[i]);
                 break;
             case NATIVE_STRING:
                 param = (*(void **) parameters[i] != NULL) ? rb_str_new2(*(char **) parameters[i]) : Qnil;
@@ -793,6 +793,9 @@ invoke_callback(VALUE data)
         case NATIVE_FLOAT64:
             *((double *) retval) = NUM2DBL(rbReturnValue);
             break;
+        case NATIVE_LONGDOUBLE:
+            *((long double *) retval) = rbffi_num2longdouble(rbReturnValue);
+            break;
         case NATIVE_POINTER:
             if (TYPE(rbReturnValue) == T_DATA && rb_obj_is_kind_of(rbReturnValue, rbffi_PointerClass)) {
                 *((void **) retval) = ((AbstractMemory *) DATA_PTR(rbReturnValue))->address;
diff --git a/spec/ffi/fixtures/ClosureTest.c b/spec/ffi/fixtures/ClosureTest.c
index 1e7574873..c477be8a7 100644
--- a/spec/ffi/fixtures/ClosureTest.c
+++ b/spec/ffi/fixtures/ClosureTest.c
@@ -35,6 +35,7 @@ R(J, long long);
 R(LL, long long);
 R(F, float);
 R(D, double);
+R(LD, long double);
 R(P, const void*);
 
 
@@ -47,6 +48,7 @@ P(J, long long);
 P(LL, long long);
 P(F, float);
 P(D, double);
+P(LD, long double);
 P(P, const void*);
 P(UL, unsigned long);
 
diff --git a/spec/ffi/long_double_spec.rb b/spec/ffi/long_double_spec.rb
index 86f60c377..3128d9686 100644
--- a/spec/ffi/long_double_spec.rb
+++ b/spec/ffi/long_double_spec.rb
@@ -7,10 +7,17 @@
 require 'bigdecimal'
 
 # long double not yet supported on TruffleRuby
-describe ":long_double arguments and return values", if: RUBY_PLATFORM !~ /mingw|mswin/ do
+describe ":long_double arguments and return values" do
   module LibTest
     extend FFI::Library
     ffi_lib TestLibrary::PATH
+
+    callback :cbVrLD, [ ], :long_double
+    attach_function :testCallbackVrLD, :testClosureVrLD, [ :cbVrLD ], :long_double
+
+    callback :cbLDrV, [ :long_double ], :void
+    attach_function :testCallbackLDrV, :testClosureLDrV, [ :cbLDrV, :long_double ], :void
+
     attach_function :add_f128, [ :long_double, :long_double ], :long_double
     attach_function :ret_f128, [ :long_double ], :long_double
   end
@@ -28,4 +35,16 @@ module LibTest
   it "add two long double numbers" do
     expect(LibTest.add_f128(0.1, 0.2)).to be_within(0.01).of(0.3)
   end
+
+  describe "Callback" do
+    it "returning :long_double" do
+      expect(LibTest.testCallbackVrLD { -0.1 }).to be_within(0.01).of(-0.1)
+    end
+
+    it ":long_double argument" do
+      v = nil
+      LibTest.testCallbackLDrV(0.1) { |i| v = i }
+      expect(v).to be_within(0.01).of(0.1)
+    end
+  end
 end if RUBY_ENGINE != "truffleruby"