diff --git a/hdtest/deflatehd.c b/hdtest/deflatehd.c
index 4054dd81..62c89a87 100644
--- a/hdtest/deflatehd.c
+++ b/hdtest/deflatehd.c
@@ -22,6 +22,10 @@
  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/hdtest/inflatehd.c b/hdtest/inflatehd.c
index 8523b1ad..0c71fc5f 100644
--- a/hdtest/inflatehd.c
+++ b/hdtest/inflatehd.c
@@ -22,6 +22,10 @@
  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/lib/nghttp2_version.c b/lib/nghttp2_version.c
index c7ec420d..7e3d8e86 100644
--- a/lib/nghttp2_version.c
+++ b/lib/nghttp2_version.c
@@ -22,6 +22,9 @@
  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
 
 #include <nghttp2/nghttp2.h>
 
diff --git a/src/base64.h b/src/base64.h
index 6d1baf4a..5e4631af 100644
--- a/src/base64.h
+++ b/src/base64.h
@@ -25,6 +25,8 @@
 #ifndef BASE64_H
 #define BASE64_H
 
+#include "nghttp2_config.h"
+
 #include <string>
 
 namespace nghttp2 {
diff --git a/src/nghttpd.cc b/src/nghttpd.cc
index aae25a67..9f3a5455 100644
--- a/src/nghttpd.cc
+++ b/src/nghttpd.cc
@@ -22,6 +22,8 @@
  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
+#include "nghttp2_config.h"
+
 #include <unistd.h>
 #include <signal.h>
 #include <getopt.h>