diff --git a/include/libunwind_i.h b/include/libunwind_i.h
index d7353d18..6bbeb3ef 100644
--- a/include/libunwind_i.h
+++ b/include/libunwind_i.h
@@ -53,6 +53,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/mman.h>
 
 #if defined(HAVE_ENDIAN_H)
 # include <endian.h>