diff --git a/cogl-color.h b/cogl-color.h
index 14c5d8413..56f75a86b 100644
--- a/cogl-color.h
+++ b/cogl-color.h
@@ -1,3 +1,7 @@
+#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
+#error "Only <cogl/cogl.h> can be included directly."
+#endif
+
 #ifndef __COGL_COLOR_H__
 #define __COGL_COLOR_H__
 
diff --git a/cogl-fixed.h b/cogl-fixed.h
index b1542bcc3..1e2709572 100644
--- a/cogl-fixed.h
+++ b/cogl-fixed.h
@@ -1,3 +1,7 @@
+#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
+#error "Only <cogl/cogl.h> can be included directly."
+#endif
+
 #ifndef __COGL_FIXED_H__
 #define __COGL_FIXED_H__
 
diff --git a/cogl.h.in b/cogl.h.in
index 3f23621f9..5b57a7e8f 100644
--- a/cogl.h.in
+++ b/cogl.h.in
@@ -42,6 +42,8 @@
 #ifndef __COGL_H__
 #define __COGL_H__
 
+#define __COGL_H_INSIDE__
+
 #include <glib.h>
 
 #include <cogl/cogl-defines-@CLUTTER_COGL@.h>
@@ -1587,4 +1589,6 @@ void            cogl_draw_buffer              (CoglBufferTarget    target,
 
 G_END_DECLS
 
+#undef __COGL_H_INSIDE__
+
 #endif /* __COGL_H__ */
diff --git a/common/Makefile.am b/common/Makefile.am
index 5a52418be..7e3d7dfc0 100644
--- a/common/Makefile.am
+++ b/common/Makefile.am
@@ -5,6 +5,7 @@ INCLUDES = \
 	-I$(top_srcdir)/clutter/cogl/$(CLUTTER_COGL) \
 	-I$(top_builddir)/clutter \
 	-I$(top_builddir)/clutter/cogl \
+        -DCLUTTER_COMPILATION \
 	$(CLUTTER_CFLAGS) \
 	$(CLUTTER_DEBUG_CFLAGS) \
 	$(GCC_FLAGS)
diff --git a/gl/Makefile.am b/gl/Makefile.am
index 2b2273078..d2a1b4a16 100644
--- a/gl/Makefile.am
+++ b/gl/Makefile.am
@@ -13,6 +13,7 @@ INCLUDES = \
 	-I$(top_srcdir)/clutter/cogl/$(CLUTTER_COGL) \
 	-I$(top_builddir)/clutter \
 	-I$(top_builddir)/clutter/cogl \
+        -DCLUTTER_COMPILATION \
 	$(CLUTTER_CFLAGS) \
 	$(CLUTTER_DEBUG_CFLAGS) \
 	$(GCC_FLAGS)
diff --git a/gles/Makefile.am b/gles/Makefile.am
index 1ac969ec3..29e25ddd2 100644
--- a/gles/Makefile.am
+++ b/gles/Makefile.am
@@ -13,6 +13,7 @@ INCLUDES = \
 	-I$(top_srcdir)/clutter/cogl/$(CLUTTER_COGL) \
 	-I$(top_builddir)/clutter \
 	-I$(top_builddir)/clutter/cogl \
+        -DCLUTTER_COMPILATION \
 	$(CLUTTER_CFLAGS) \
 	$(CLUTTER_DEBUG_CFLAGS) \
 	$(GCC_FLAGS)