diff --git a/src/Makefile.am b/src/Makefile.am
index df5c52f..93a5138 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -146,6 +146,7 @@
 	check-c-linkage-decls.sh \
 	check-header-guards.sh \
 	check-internal-symbols.sh \
+	check-includes.sh \
 	$(NULL)
 
 if HAVE_ICU
@@ -154,5 +155,11 @@
 endif
 
 TESTS = $(dist_check_SCRIPTS)
+TESTS_ENVIRONMENT = \
+	srcdir="$(srcdir)" \
+	MAKE="$(MAKE) $(AM_MAKEFLAGS)" \
+	HBSOURCES="$(HBSOURCES)" \
+	HBHEADERS="$(HBHEADERS)" \
+	$(NULL)
 
 -include $(top_srcdir)/git.mk
diff --git a/src/check-c-linkage-decls.sh b/src/check-c-linkage-decls.sh
index ffdb9e3..84e77cf 100755
--- a/src/check-c-linkage-decls.sh
+++ b/src/check-c-linkage-decls.sh
@@ -6,9 +6,13 @@
 test -z "$srcdir" && srcdir=.
 stat=0
 
+test "x$HBHEADERS" = x && HBHEADERS=`find . -maxdepth 1 -name 'hb*.h'`
+test "x$HBSOURCES" = x && HBSOURCES=`find . -maxdepth 1 -name 'hb-*.cc' -or -name 'hb-*.hh'`
+
+
 cd "$srcdir"
 
-for x in hb-*.cc hb-*.h hb-*.hh ; do
+for x in $HBHEADERS $HBSOURCES; do
 	if ! grep -q HB_BEGIN_DECLS "$x" || ! grep -q HB_END_DECLS "$x"; then
 		echo "Ouch, file $x does not HB_BEGIN_DECLS / HB_END_DECLS"
 		stat=1
diff --git a/src/check-header-guards.sh b/src/check-header-guards.sh
index c966cd2..ddbcd83 100755
--- a/src/check-header-guards.sh
+++ b/src/check-header-guards.sh
@@ -6,9 +6,15 @@
 test -z "$srcdir" && srcdir=.
 stat=0
 
+test "x$HBHEADERS" = x && HBHEADERS=`find . -maxdepth 1 -name 'hb*.h'`
+test "x$HBSOURCES" = x && HBSOURCES=`find . -maxdepth 1 -name 'hb-*.cc' -or -name 'hb-*.hh'`
+
+
 cd "$srcdir"
 
-for x in hb-*.h hb-*.hh ; do
+for x in $HBHEADERS $HBSOURCES; do
+	echo "$x" | grep '[^h]$' -q && continue;
+	x=`echo "$x" | sed 's@.*/@@'`
 	tag=`echo "$x" | tr 'a-z.-' 'A-Z_'`
 	lines=`grep "\<$tag\>" "$x" | wc -l`
 	if test "x$lines" != x3; then
diff --git a/src/check-includes.sh b/src/check-includes.sh
new file mode 100755
index 0000000..79323a7
--- /dev/null
+++ b/src/check-includes.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+LC_ALL=C
+export LC_ALL
+
+test -z "$srcdir" && srcdir=.
+stat=0
+
+test "x$HBHEADERS" = x && HBHEADERS=`find . -maxdepth 1 -name 'hb*.h'`
+test "x$HBSOURCES" = x && HBSOURCES=`find . -maxdepth 1 -name 'hb-*.cc' -or -name 'hb-*.hh'`
+
+
+cd "$srcdir"
+
+
+echo 'Checking that public header files #include "hb-common.h" or "hb.h" first (or none)'
+
+for x in $HBHEADERS; do
+	grep '#.*\<include\>' "$x" /dev/null | head -n 1
+done |
+grep -v '"hb-common[.]h"' |
+grep -v '"hb[.]h"' |
+grep -v 'hb-common[.]h:' |
+grep -v 'hb[.]h:' |
+grep . >&2 && stat=1
+
+
+echo 'Checking that source files #include "hb-*private.hh" first (or none)'
+
+for x in $HBSOURCES; do
+	grep '#.*\<include\>' "$x" /dev/null | head -n 1
+done |
+grep -v '"hb-.*private[.]hh"' |
+grep -v 'hb-private[.]hh:' |
+grep . >&2 && stat=1
+
+
+echo 'Checking that there is no #include <hb.*.h>'
+grep '#.*\<include\>.*<.*hb' $HBHEADERS $HBSOURCES >&2 && stat=1
+
+
+exit $stat
diff --git a/src/check-internal-symbols.sh b/src/check-internal-symbols.sh
index 124a7b0..2885fa4 100755
--- a/src/check-internal-symbols.sh
+++ b/src/check-internal-symbols.sh
@@ -3,6 +3,10 @@
 LC_ALL=C
 export LC_ALL
 
+test -z "$srcdir" && srcdir=.
+stat=0
+
+
 if which nm 2>/dev/null >/dev/null; then
 	:
 else
@@ -10,10 +14,6 @@
 	exit 0
 fi
 
-test -z "$srcdir" && srcdir=.
-test -z "$MAKE" && MAKE=make
-stat=0
-
 so=.libs/libharfbuzz.so
 if test -f "$so"; then
 	echo "Checking that we are exposing internal symbols"
diff --git a/src/check-libstdc++.sh b/src/check-libstdc++.sh
index c0abcbe..40e73b0 100755
--- a/src/check-libstdc++.sh
+++ b/src/check-libstdc++.sh
@@ -3,6 +3,10 @@
 LC_ALL=C
 export LC_ALL
 
+test -z "$srcdir" && srcdir=.
+stat=0
+
+
 if which ldd 2>/dev/null >/dev/null; then
 	:
 else
@@ -10,9 +14,6 @@
 	exit 0
 fi
 
-test -z "$srcdir" && srcdir=.
-stat=0
-
 so=.libs/libharfbuzz.so
 if test -f "$so"; then
 	echo "Checking that we are not linking to libstdc++"
diff --git a/src/hb-ot-shape.h b/src/hb-ot-shape.h
index 70a8172..f9560e5 100644
--- a/src/hb-ot-shape.h
+++ b/src/hb-ot-shape.h
@@ -27,6 +27,7 @@
 #ifndef HB_OT_SHAPE_H
 #define HB_OT_SHAPE_H
 
+#include "hb-common.h"
 #include "hb-shape.h"