diff --git a/src/plugins/instantiate/stdlib/calloc.mli b/src/plugins/instantiate/stdlib/calloc.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..6ad873cc0821c4948e2ed1c785f5d718055d953b 100644
--- a/src/plugins/instantiate/stdlib/calloc.mli
+++ b/src/plugins/instantiate/stdlib/calloc.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for calloc. Nothing is exported. *)
diff --git a/src/plugins/instantiate/stdlib/free.mli b/src/plugins/instantiate/stdlib/free.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..49d1d0397e263a1d99f038d5fca96113e1f216b0 100644
--- a/src/plugins/instantiate/stdlib/free.mli
+++ b/src/plugins/instantiate/stdlib/free.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for free. Nothing is exported. *)
diff --git a/src/plugins/instantiate/stdlib/malloc.mli b/src/plugins/instantiate/stdlib/malloc.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..cb602ba318dd2c7bd03fb97256a43bf463a792ef 100644
--- a/src/plugins/instantiate/stdlib/malloc.mli
+++ b/src/plugins/instantiate/stdlib/malloc.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for malloc. Nothing is exported. *)
diff --git a/src/plugins/instantiate/string/memcmp.mli b/src/plugins/instantiate/string/memcmp.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..0e837c30d2f17b20d951419cb652b3a1b69556ab 100644
--- a/src/plugins/instantiate/string/memcmp.mli
+++ b/src/plugins/instantiate/string/memcmp.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for memcmp. Nothing is exported. *)
diff --git a/src/plugins/instantiate/string/memcpy.mli b/src/plugins/instantiate/string/memcpy.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..afc53006e4bdc810836ea8fa9df11abe24fc603a 100644
--- a/src/plugins/instantiate/string/memcpy.mli
+++ b/src/plugins/instantiate/string/memcpy.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for memcpy. Nothing is exported. *)
diff --git a/src/plugins/instantiate/string/memmove.mli b/src/plugins/instantiate/string/memmove.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..d290ece40994a2f7f1d611e650cb7826a366b73a 100644
--- a/src/plugins/instantiate/string/memmove.mli
+++ b/src/plugins/instantiate/string/memmove.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for memmove. Nothing is exported. *)
diff --git a/src/plugins/instantiate/string/memset.mli b/src/plugins/instantiate/string/memset.mli
index 182bc40a8e1af00f6d1329952d449d0f2e6808e1..dae107989326e35ed5de1e9cae12a0b4914e2099 100644
--- a/src/plugins/instantiate/string/memset.mli
+++ b/src/plugins/instantiate/string/memset.mli
@@ -19,3 +19,5 @@
 (*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
 (*                                                                        *)
 (**************************************************************************)
+
+(* register instantiation for memset. Don't export anything *)