diff --git a/ChangeLog b/ChangeLog
index 3e634c83b..568645264 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,8 @@
 - TD-45 Fix preprocessor define (thanks to Jochen Sprickerhof).
 - TD-55 TLSServer/Client need to include <errno.h> on Solaris (thanks to Tatjana
         Heuser).
+- TD-56 File.cpp needs to include <string.h> on Solaris (thanks to Tatjana
+        Heuѕer).
 - #1255 l10n translation utility improvements (thanks to Renato Alves).
 - #1473 Make TASK_RCDIR customizable (thanks to Elias Probst).
 - #1486 Truncated sentence in task-sync(5) manpage (thanks to Jakub Wilk).
diff --git a/src/File.cpp b/src/File.cpp
index 6c4e0080a..1712ee786 100644
--- a/src/File.cpp
+++ b/src/File.cpp
@@ -28,7 +28,12 @@
 #include <fstream>
 #include <sys/types.h>
 #include <sys/stat.h>
+#ifdef SOLARIS
+#include <fcntl.h> // for flock() replacement
+#include <string.h> // for memset()
+#else
 #include <sys/file.h>
+#endif
 #include <pwd.h>
 #include <unistd.h>
 #include <File.h>