diff --git a/Makefile.am b/Makefile.am
index 45feab1d..9a9130c4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2,6 +2,7 @@
 
 AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
+	-I$(top_srcdir) \
 	-I$(top_srcdir)/include \
 	-DLOCALEDIR=\"$(localedir)\"
 
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 56c36a2f..f09cb8c0 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,4 +1,7 @@
-AM_CPPFLAGS = -include $(top_builddir)/config.h -I$(top_srcdir)/include
+AM_CPPFLAGS = \
+	-include $(top_builddir)/config.h \
+	-I$(top_srcdir) \
+	-I$(top_srcdir)/include
 
 AM_CPPFLAGS += -DTEST_PROGRAM
 
diff --git a/proc/Makefile.am b/proc/Makefile.am
index f000dbcb..5b0e84cc 100644
--- a/proc/Makefile.am
+++ b/proc/Makefile.am
@@ -1,6 +1,7 @@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
+	-I$(top_srcdir) \
 	-I$(top_srcdir)/include \
 	-DLOCALEDIR=\"$(localedir)\"
 
diff --git a/ps/Makefile.am b/ps/Makefile.am
index e46f496f..c8e949aa 100644
--- a/ps/Makefile.am
+++ b/ps/Makefile.am
@@ -1,5 +1,6 @@
 AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
+	-I$(top_srcdir) \
 	-I$(top_srcdir)/include \
 	-DLOCALEDIR=\"$(localedir)\"
 
diff --git a/top/Makefile.am b/top/Makefile.am
index bba36bc9..0cad3195 100644
--- a/top/Makefile.am
+++ b/top/Makefile.am
@@ -1,5 +1,6 @@
 AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
+	-I$(top_srcdir) \
 	-I$(top_srcdir)/include \
 	-DLOCALEDIR=\"$(localedir)\"