diff --git a/libisofs/filters/external.c b/libisofs/filters/external.c
index 0593773..1105ec5 100644
--- a/libisofs/filters/external.c
+++ b/libisofs/filters/external.c
@@ -13,6 +13,10 @@
  * 
  */
 
+#ifdef HAVE_CONFIG_H
+#include "../config.h"
+#endif
+
 #include "../libisofs.h"
 #include "../filter.h"
 #include "../fsource.h"
diff --git a/libisofs/filters/gzip.c b/libisofs/filters/gzip.c
index 0f0ed2b..de73696 100644
--- a/libisofs/filters/gzip.c
+++ b/libisofs/filters/gzip.c
@@ -17,6 +17,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#include "../config.h"
+#endif
+
 #include "../libisofs.h"
 #include "../filter.h"
 #include "../fsource.h"
diff --git a/libisofs/filters/xor_encrypt.c b/libisofs/filters/xor_encrypt.c
index 7d88508..69bb49b 100644
--- a/libisofs/filters/xor_encrypt.c
+++ b/libisofs/filters/xor_encrypt.c
@@ -7,6 +7,10 @@
  * See COPYING file for details.
  */
 
+#ifdef HAVE_CONFIG_H
+#include "../config.h"
+#endif
+
 #include "../libisofs.h"
 #include "../filter.h"
 #include "../fsource.h"
diff --git a/libisofs/filters/zisofs.c b/libisofs/filters/zisofs.c
index 1e99f66..e34092d 100644
--- a/libisofs/filters/zisofs.c
+++ b/libisofs/filters/zisofs.c
@@ -14,6 +14,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#include "../config.h"
+#endif
+
 #include "../libisofs.h"
 #include "../filter.h"
 #include "../fsource.h"