diff --git a/m-bitset.h b/m-bitset.h
index e7e17ed6..2e979471 100644
--- a/m-bitset.h
+++ b/m-bitset.h
@@ -39,6 +39,8 @@ typedef struct bitset_s {
   size_t alloc;           // Alloc is the number of allocated limbs
   bitset_limb *ptr;       // Pointer to the allocated limbs
 } bitset_t[1];
+typedef struct bitset_s *bitset_ptr;
+typedef const struct bitset_s bitset_srcptr;
 
 typedef struct bitset_it_s {
   size_t index;           // index to the array of bit
diff --git a/m-string.h b/m-string.h
index 0fa3fcbc..8d4b9329 100644
--- a/m-string.h
+++ b/m-string.h
@@ -73,6 +73,8 @@ typedef struct string_s {
   size_t size, alloc;
   char *ptr;
 } string_t[1];
+typedef struct string_s *string_ptr;
+typedef const struct string_s string_srcptr;
 
 /* Input option for the fgets function */
 typedef enum string_fgets_s {