diff --git a/arif.pc.in b/arif.pc.in
index 6055ac7..3398003 100644
--- a/arif.pc.in
+++ b/arif.pc.in
@@ -13,11 +13,10 @@ prefix=@prefix@
 exec_prefix=@exec_prefix@
 libdir=@libdir@
 includedir=@includedir@
-pkgincludedir=${includedir}/${package}
 
 Name: ${package}
 Description: Another Readline Input Framework
 Version: ${version}
 URL: https://nongnu.org/arif
 Libs: -L${libdir} -larif
-Cflags: -I${includedir} -I${pkgincludedir}
+Cflags: -I${includedir}
diff --git a/doc/arif_ctx_create.3 b/doc/arif_ctx_create.3
index fad30cb..65d0814 100644
--- a/doc/arif_ctx_create.3
+++ b/doc/arif_ctx_create.3
@@ -5,7 +5,7 @@ arif_ctx_create - create input context
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif.h>
+.B #include <arif.h>
 .PP
 .B struct arif_ctx *
 .B arif_ctx_create (
diff --git a/doc/arif_ctx_destroy.3 b/doc/arif_ctx_destroy.3
index 677fc97..5320c9a 100644
--- a/doc/arif_ctx_destroy.3
+++ b/doc/arif_ctx_destroy.3
@@ -5,7 +5,7 @@ arif_ctx_destroy - destroy input context
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif.h>
+.B #include <arif.h>
 .PP
 .B void
 .B arif_ctx_destroy (
diff --git a/doc/arif_fetch.3 b/doc/arif_fetch.3
index 105391b..0d91039 100644
--- a/doc/arif_fetch.3
+++ b/doc/arif_fetch.3
@@ -5,7 +5,7 @@ arif_fetch - fetch candidates
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif.h>
+.B #include <arif.h>
 .PP
 .B int
 .B arif_fetch (
diff --git a/doc/arif_query.3 b/doc/arif_query.3
index 1c2e45f..65b9d4b 100644
--- a/doc/arif_query.3
+++ b/doc/arif_query.3
@@ -5,7 +5,7 @@ arif_query - query for candidates
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif.h>
+.B #include <arif.h>
 .PP
 .B int
 .B arif_query (
diff --git a/doc/arif_rl_complete.3 b/doc/arif_rl_complete.3
index 1dc0389..31defd2 100644
--- a/doc/arif_rl_complete.3
+++ b/doc/arif_rl_complete.3
@@ -5,7 +5,7 @@ arif_rl_complete - generate Readline completion candidates
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif_rl.h>
+.B #include <arif_rl.h>
 .PP
 .B char **
 .B arif_rl_complete (
diff --git a/doc/arif_rl_display.3 b/doc/arif_rl_display.3
index e3b162c..5778ee5 100644
--- a/doc/arif_rl_display.3
+++ b/doc/arif_rl_display.3
@@ -5,7 +5,7 @@ arif_rl_display - display Readline completion candidates
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif_rl.h>
+.B #include <arif_rl.h>
 .PP
 .B void
 .B arif_rl_display (
diff --git a/doc/arif_select_page.3 b/doc/arif_select_page.3
index 37f21e4..7e9cffe 100644
--- a/doc/arif_select_page.3
+++ b/doc/arif_select_page.3
@@ -5,7 +5,7 @@ arif_select_page - select the page of candidates
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif.h>
+.B #include <arif.h>
 .PP
 .B int
 .B arif_select_page (
diff --git a/doc/arif_set_engine.3 b/doc/arif_set_engine.3
index acf4d28..6b4d4cb 100644
--- a/doc/arif_set_engine.3
+++ b/doc/arif_set_engine.3
@@ -5,7 +5,7 @@ arif_set_engine - set input method engine
 .
 .SH SYNOPSIS
 .EX
-.B #include <arif/arif.h>
+.B #include <arif.h>
 .PP
 .B void
 .B arif_set_engine (
diff --git a/include/Makefile.am b/include/Makefile.am
index 2aa4988..7c7530e 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -6,13 +6,13 @@
 # this notice are preserved. This file is offered as-is, without any warranty.
 #
 
-noinst_HEADERS     = arif_defs.h arify.h
-pkginclude_HEADERS = arif.h
+noinst_HEADERS  = arif_defs.h arify.h
+include_HEADERS = arif.h
 
 
 if BUILD_ARIF_READLINE
 
-  noinst_HEADERS     += arify_rl.h
-  pkginclude_HEADERS += arif_rl.h
+  noinst_HEADERS  += arify_rl.h
+  include_HEADERS += arif_rl.h
 
 endif  # BUILD_ARIF_READLINE