diff --git a/repos/libports/lib/mk/libc.mk b/repos/libports/lib/mk/libc.mk
index 26ed6881a..4aa7a1205 100644
--- a/repos/libports/lib/mk/libc.mk
+++ b/repos/libports/lib/mk/libc.mk
@@ -14,7 +14,8 @@ SRC_CC = atexit.cc dummies.cc rlimit.cc sysctl.cc \
          gettimeofday.cc malloc.cc progname.cc fd_alloc.cc file_operations.cc \
          plugin.cc plugin_registry.cc select.cc exit.cc environ.cc nanosleep.cc \
          libc_mem_alloc.cc pread_pwrite.cc readv_writev.cc poll.cc \
-         libc_pdbg.cc vfs_plugin.cc rtc.cc dynamic_linker.cc socket_operations.cc
+         libc_pdbg.cc vfs_plugin.cc rtc.cc dynamic_linker.cc signal.cc \
+         socket_operations.cc
 
 INC_DIR += $(REP_DIR)/src/lib/libc
 
diff --git a/repos/libports/src/lib/libc/dummies.cc b/repos/libports/src/lib/libc/dummies.cc
index 3e96ed2f5..4c6e0c229 100644
--- a/repos/libports/src/lib/libc/dummies.cc
+++ b/repos/libports/src/lib/libc/dummies.cc
@@ -30,7 +30,6 @@ extern "C" {
 
 #include <db.h>
 #include <netdb.h>
-#include <signal.h>
 #include <unistd.h>
 #include <pthread.h>
 #include <pwd.h>
@@ -118,8 +117,6 @@ DUMMY(int   , -1, _sigaction, (int, const struct sigaction *, struct sigaction *
 DUMMY(int   , -1, sigaction, (int, const struct sigaction *, struct sigaction *))
 DUMMY(int   , -1, sigblock, (int))
 DUMMY(int   , -1, sigpause, (int))
-DUMMY(int   , -1, _sigprocmask, (int, const sigset_t *, sigset_t *))
-DUMMY(int   , -1, sigprocmask, (int, const sigset_t *, sigset_t *))
 DUMMY(int   , -1, _sigsuspend, (const sigset_t *))
 DUMMY(int   , -1, sigsuspend, (const sigset_t *))
 DUMMY(int   , -1, socketpair, (int, int, int, int *))
diff --git a/repos/libports/src/lib/libc/signal.cc b/repos/libports/src/lib/libc/signal.cc
new file mode 100644
index 000000000..5017863f0
--- /dev/null
+++ b/repos/libports/src/lib/libc/signal.cc
@@ -0,0 +1,43 @@
+/*
+ * \brief  POSIX signals
+ * \author Emery Hemingway
+ * \date   2015-10-30
+ */
+
+/*
+ * Copyright (C) 2006-2015 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+/* libc includes */
+extern "C" {
+#include <signal.h>
+#include <stdlib.h>
+#include <errno.h>
+}
+
+
+extern "C" int __attribute__((weak)) sigprocmask(int how, const sigset_t *set, sigset_t *old_set)
+{
+	/* no signals should be expected, so report all signals blocked */
+	if (old_set != NULL)
+		sigfillset(old_set);
+
+	if (set == NULL)
+		return 0;
+
+	switch (how) {
+	case SIG_BLOCK:   return 0;
+	case SIG_SETMASK: return 0;
+	case SIG_UNBLOCK: return 0;
+	}
+	errno = EINVAL;
+	return -1;
+}
+
+extern "C" int __attribute__((weak)) _sigprocmask(int how, const sigset_t *set, sigset_t *old_set)
+{
+	return sigprocmask(how, set, old_set);
+}