diff --git a/girepository/gdump.c b/girepository/gdump.c
index caf2973bb..29bcfb676 100644
--- a/girepository/gdump.c
+++ b/girepository/gdump.c
@@ -32,7 +32,7 @@
  * to libgirepository; see
  * https://bugzilla.gnome.org/show_bug.cgi?id=630342
  */
-#ifdef G_IREPOSITORY_COMPILATION
+#ifdef GI_COMPILATION
 #include "config.h"
 #include "girepository.h"
 #endif
@@ -543,7 +543,7 @@ dump_error_quark (GQuark quark, const char *symbol, GOutputStream *out)
  *
  * Returns: %TRUE on success, %FALSE on error
  */
-#ifndef G_IREPOSITORY_COMPILATION
+#ifndef GI_COMPILATION
 static gboolean
 dump_irepository (const char *arg, GError **error) G_GNUC_UNUSED;
 static gboolean
diff --git a/girepository/girepository.h b/girepository/girepository.h
index 511ef30eb..1bac63ffc 100644
--- a/girepository/girepository.h
+++ b/girepository/girepository.h
@@ -247,4 +247,6 @@ void gi_cclosure_marshal_generic (GClosure       *closure,
 
 G_END_DECLS
 
+#undef __GIREPOSITORY_H_INSIDE__
+
 #endif  /* __G_IREPOSITORY_H__ */
diff --git a/girepository/girffi.h b/girepository/girffi.h
index 28de33b19..359a5d36a 100644
--- a/girepository/girffi.h
+++ b/girepository/girffi.h
@@ -24,6 +24,10 @@
 #ifndef __GIRFFI_H__
 #define __GIRFFI_H__
 
+#if !defined (__GIREPOSITORY_H_INSIDE__) && !defined (GI_COMPILATION)
+#error "Only <girepository.h> can be included directly."
+#endif
+
 #include <ffi.h>
 #include "girepository.h"
 
diff --git a/girepository/meson.build b/girepository/meson.build
index 477994c65..9e3a3275d 100644
--- a/girepository/meson.build
+++ b/girepository/meson.build
@@ -67,7 +67,7 @@ girepo_headers = files(
 install_headers(girepo_headers, install_dir: gir_includedir)
 
 gir_c_args = [
-  '-DG_IREPOSITORY_COMPILATION',
+  '-DGI_COMPILATION',
   '-DG_LOG_DOMAIN="GLib-GIRepository"',
   '-DGIR_SUFFIX="gir-1.0"',
   '-DGIR_DIR="@0@"'.format(glib_girdir),