diff --git a/src/c/gbc.d b/src/c/gbc.d
index 947678ff5..5654ef40a 100644
--- a/src/c/gbc.d
+++ b/src/c/gbc.d
@@ -598,6 +598,8 @@ sweep_phase(void)
 			if (x->d.m == FREE)
 				continue;
 			else if (x->d.m) {
+				/* FIXME!!! Here should come a finalization
+				   procedure for streams */
 				x->d.m = FALSE;
 				continue;
 			}
diff --git a/src/c/symbols_list.h b/src/c/symbols_list.h
index 66101cf35..04c7d2df0 100644
--- a/src/c/symbols_list.h
+++ b/src/c/symbols_list.h
@@ -1027,6 +1027,7 @@ cl_symbols[] = {
 {SYS_ "CHAR-SET", SI_ORDINARY, si_char_set, 3},
 {SYS_ "CHDIR", SI_ORDINARY, si_chdir, 1},
 {SYS_ "CLEAR-COMPILER-PROPERTIES", SI_ORDINARY, cl_identity, 1},
+{SYS_ "CLOSE-PIPE", SI_ORDINARY, si_close_pipe, 1},
 {SYS_ "COERCE-TO-FUNCTION", SI_ORDINARY, si_coerce_to_function, 1},
 {SYS_ "COERCE-TO-PACKAGE", SI_ORDINARY, si_coerce_to_package, 1},
 {SYS_ "COMPILED-FUNCTION-BLOCK", SI_ORDINARY, si_compiled_function_block, 1},
diff --git a/src/c/unixsys.d b/src/c/unixsys.d
index 6f4b85a98..39668a05e 100644
--- a/src/c/unixsys.d
+++ b/src/c/unixsys.d
@@ -38,21 +38,34 @@ si_system(cl_object cmd)
 cl_object
 si_open_pipe(cl_object cmd)
 {
-  FILE *ptr;
-  cl_object stream;
+	FILE *ptr;
+	cl_object stream;
 
-  assert_type_string(cmd);
- 
-  if ((ptr = popen(cmd->string.self, OPEN_R)) == NULL)
-    @(return Cnil)
-  stream = cl_alloc_object(t_stream);
-  stream->stream.mode = smm_input;
-  stream->stream.file = ptr;
-  stream->stream.object0 = @'base-char';
-  stream->stream.object1 = cmd;
-  stream->stream.int0 = stream->stream.int1 = 0;
+	assert_type_string(cmd);
+	ptr = popen(cmd->string.self, "r");
+	if (ptr == NULL)
+		@(return Cnil);
+	stream = cl_alloc_object(t_stream);
+	stream->stream.mode = smm_input;
+	stream->stream.file = ptr;
+	stream->stream.object0 = @'base-char';
+	stream->stream.object1 = @'si::open-pipe';
+	stream->stream.int0 = stream->stream.int1 = 0;
 #if !defined(GBC_BOEHM)
-  setbuf(ptr, stream->stream.buffer = cl_alloc_atomic(BUFSIZ));
+	setbuf(ptr, stream->stream.buffer = cl_alloc_atomic(BUFSIZ));
 #endif
-  @(return stream)
+	@(return stream)
+}
+
+cl_object
+si_close_pipe(cl_object stream)
+{
+	if (type_of(stream) == t_stream &&
+	    stream->stream.object1 == @'si::open-pipe') {
+		stream->stream.mode = smm_closed;
+		pclose(stream->stream.file);
+		stream->stream.file = NULL;
+		stream->stream.object0 = OBJNULL;
+	}
+	@(return)
 }
diff --git a/src/h/external.h b/src/h/external.h
index 4528c607b..5ae7d8b8c 100644
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -1353,6 +1353,7 @@ extern void init_interrupt(void);
 
 extern cl_object si_system(cl_object cmd);
 extern cl_object si_open_pipe(cl_object cmd);
+extern cl_object si_close_pipe(cl_object stream);
 
 #ifdef __cplusplus
 }