diff --git a/girepository/girmodule-private.h b/girepository/girmodule-private.h
index 8f1d62887..9db6b42db 100644
--- a/girepository/girmodule-private.h
+++ b/girepository/girmodule-private.h
@@ -37,7 +37,7 @@ struct _GIIrTypelibBuild {
   GHashTable  *types;
   GList       *nodes_with_attributes;
   uint32_t     n_attributes;
-  guchar      *data;
+  uint8_t     *data;
   GList       *stack; 
 };
 
diff --git a/girepository/girmodule.c b/girepository/girmodule.c
index 20c592aa2..9ed3a7509 100644
--- a/girepository/girmodule.c
+++ b/girepository/girmodule.c
@@ -191,7 +191,7 @@ gi_ir_module_add_include_module (GIIrModule *module,
 struct AttributeWriteData
 {
   unsigned int count;
-  guchar *databuf;
+  uint8_t *databuf;
   GIIrNode *node;
   GHashTable *strings;
   uint32_t *offset;
@@ -218,7 +218,7 @@ static unsigned
 write_attributes (GIIrModule *module,
                   GIIrNode   *node,
                   GHashTable *strings,
-                  guchar     *data,
+                  uint8_t    *data,
                   uint32_t   *offset,
                   uint32_t   *offset2)
 {
diff --git a/girepository/girnode-private.h b/girepository/girnode-private.h
index 8cd5d4a40..51cfe6647 100644
--- a/girepository/girnode-private.h
+++ b/girepository/girnode-private.h
@@ -381,7 +381,7 @@ void      gi_ir_node_add_member      (GIIrNode         *node,
                                       GIIrNodeFunction *member);
 uint32_t  gi_ir_write_string         (const char  *str,
                                       GHashTable  *strings,
-                                      guchar      *data,
+                                      uint8_t     *data,
                                       uint32_t    *offset);
 
 const char * gi_ir_node_param_direction_string (GIIrNodeParam * node);
diff --git a/girepository/girnode.c b/girepository/girnode.c
index 3fa0b9c54..95ba5b14c 100644
--- a/girepository/girnode.c
+++ b/girepository/girnode.c
@@ -1405,7 +1405,7 @@ gi_ir_node_build_typelib (GIIrNode         *node,
   gboolean appended_stack;
   GHashTable *strings = build->strings;
   GHashTable *types = build->types;
-  guchar *data = build->data;
+  uint8_t *data = build->data;
   GList *l;
   uint32_t old_offset = *offset;
   uint32_t old_offset2 = *offset2;
@@ -2414,7 +2414,7 @@ gi_ir_node_build_typelib (GIIrNode         *node,
 uint32_t
 gi_ir_write_string (const char  *str,
                     GHashTable  *strings,
-                    guchar      *data,
+                    uint8_t     *data,
                     uint32_t    *offset)
 {
   uint32_t start;
diff --git a/girepository/gitypelib-internal.h b/girepository/gitypelib-internal.h
index 6e7a1e8f6..ceff41d01 100644
--- a/girepository/gitypelib-internal.h
+++ b/girepository/gitypelib-internal.h
@@ -1313,7 +1313,7 @@ typedef struct {
 
 struct _GITypelib {
   /*< private >*/
-  guchar *data;
+  uint8_t *data;
   gsize len;
   gboolean owns_memory;
   GMappedFile *mfile;
diff --git a/girepository/gitypelib.c b/girepository/gitypelib.c
index f670332da..1a990c5dd 100644
--- a/girepository/gitypelib.c
+++ b/girepository/gitypelib.c
@@ -522,7 +522,7 @@ get_string_nofail (GITypelib *typelib, uint32_t offset)
 static gboolean
 validate_name (GITypelib   *typelib,
                const char *msg,
-               const guchar *data,
+               const uint8_t *data,
                uint32_t offset,
                GError **error)
 {
@@ -2439,7 +2439,7 @@ gi_typelib_new_from_memory (uint8_t *memory,
  * Since: 2.80
  */
 GITypelib *
-gi_typelib_new_from_const_memory (const guchar  *memory,
+gi_typelib_new_from_const_memory (const uint8_t  *memory,
                                   gsize          len,
                                   GError       **error)
 {
@@ -2449,7 +2449,7 @@ gi_typelib_new_from_const_memory (const guchar  *memory,
     return NULL;
 
   meta = g_slice_new0 (GITypelib);
-  meta->data = (guchar *) memory;
+  meta->data = (uint8_t *) memory;
   meta->len = len;
   meta->owns_memory = FALSE;
   meta->modules = NULL;