diff --git a/repos/libports/include/libc-plugin/plugin.h b/repos/libports/include/libc-plugin/plugin.h
index 561729b072..02e3a0baa9 100644
--- a/repos/libports/include/libc-plugin/plugin.h
+++ b/repos/libports/include/libc-plugin/plugin.h
@@ -110,7 +110,7 @@ namespace Libc {
 			virtual int getsockopt(File_descriptor *, int level,
 			                       int optname, void *optval,
 			                       socklen_t *optlen);
-			virtual int ioctl(File_descriptor *, int request, char *argp);
+			virtual int ioctl(File_descriptor *, unsigned long request, char *argp);
 			virtual int listen(File_descriptor *, int backlog);
 			virtual ::off_t lseek(File_descriptor *, ::off_t offset, int whence);
 			virtual int mkdir(const char *pathname, mode_t mode);
diff --git a/repos/libports/lib/symbols/libc b/repos/libports/lib/symbols/libc
index 2975880145..6f870603c9 100644
--- a/repos/libports/lib/symbols/libc
+++ b/repos/libports/lib/symbols/libc
@@ -1029,7 +1029,7 @@ _ZN4Libc6Plugin5closeEPNS_15File_descriptorE T
 _ZN4Libc6Plugin5fcntlEPNS_15File_descriptorEil T
 _ZN4Libc6Plugin5fstatEPNS_15File_descriptorEP4stat T
 _ZN4Libc6Plugin5fsyncEPNS_15File_descriptorE T
-_ZN4Libc6Plugin5ioctlEPNS_15File_descriptorEiPc T
+_ZN4Libc6Plugin5ioctlEPNS_15File_descriptorEmPc T
 _ZN4Libc6Plugin5lseekEPNS_15File_descriptorEli T
 _ZN4Libc6Plugin5lseekEPNS_15File_descriptorExi T
 _ZN4Libc6Plugin5mkdirEPKct T
diff --git a/repos/libports/src/lib/libc/file_operations.cc b/repos/libports/src/lib/libc/file_operations.cc
index 6e61039f91..f34a1df652 100644
--- a/repos/libports/src/lib/libc/file_operations.cc
+++ b/repos/libports/src/lib/libc/file_operations.cc
@@ -375,7 +375,7 @@ __SYS_(ssize_t, getdirentries, (int libc_fd, char *buf, ::size_t nbytes, ::off_t
 	FD_FUNC_WRAPPER(getdirentries, libc_fd, buf, nbytes, basep); })
 
 
-__SYS_(int, ioctl, (int libc_fd, int request, char *argp), {
+__SYS_(int, ioctl, (int libc_fd, unsigned long request, char *argp), {
 	FD_FUNC_WRAPPER(ioctl, libc_fd, request, argp); })
 
 
diff --git a/repos/libports/src/lib/libc/internal/vfs_plugin.h b/repos/libports/src/lib/libc/internal/vfs_plugin.h
index f056ed17f5..9dbce47704 100644
--- a/repos/libports/src/lib/libc/internal/vfs_plugin.h
+++ b/repos/libports/src/lib/libc/internal/vfs_plugin.h
@@ -91,7 +91,7 @@ class Libc::Vfs_plugin : public Plugin
 		 */
 		void _vfs_write_mtime(Vfs::Vfs_handle&);
 
-		int _legacy_ioctl(File_descriptor *, int , char *);
+		int _legacy_ioctl(File_descriptor *, unsigned long, char *);
 
 		/**
 		 * Call functor 'fn' with ioctl info for the given file descriptor 'fd'
@@ -177,7 +177,7 @@ class Libc::Vfs_plugin : public Plugin
 		int     fsync(File_descriptor *fd) override;
 		int     ftruncate(File_descriptor *, ::off_t) override;
 		ssize_t getdirentries(File_descriptor *, char *, ::size_t , ::off_t *) override;
-		int     ioctl(File_descriptor *, int , char *) override;
+		int     ioctl(File_descriptor *, unsigned long, char *) override;
 		::off_t lseek(File_descriptor *fd, ::off_t offset, int whence) override;
 		int     mkdir(const char *, mode_t) override;
 		File_descriptor *open(const char *path, int flags) override;
diff --git a/repos/libports/src/lib/libc/plugin.cc b/repos/libports/src/lib/libc/plugin.cc
index 75693078df..2b70a54a11 100644
--- a/repos/libports/src/lib/libc/plugin.cc
+++ b/repos/libports/src/lib/libc/plugin.cc
@@ -184,7 +184,7 @@ DUMMY(ssize_t, -1, getdirentries, (File_descriptor *, char *, ::size_t, ::off_t
 DUMMY(int,     -1, getpeername,   (File_descriptor *, struct sockaddr *, socklen_t *));
 DUMMY(int,     -1, getsockname,   (File_descriptor *, struct sockaddr *, socklen_t *));
 DUMMY(int,     -1, getsockopt,    (File_descriptor *, int, int, void *, socklen_t *));
-DUMMY(int,     -1, ioctl,         (File_descriptor *, int, char*));
+DUMMY(int,     -1, ioctl,         (File_descriptor *, unsigned long, char*));
 DUMMY(int,     -1, listen,        (File_descriptor *, int));
 DUMMY(::off_t, -1, lseek,         (File_descriptor *, ::off_t, int));
 DUMMY(ssize_t, -1, read,          (File_descriptor *, void *, ::size_t));
diff --git a/repos/libports/src/lib/libc/socket_fs_plugin.cc b/repos/libports/src/lib/libc/socket_fs_plugin.cc
index 749674fc40..74ce0a61c2 100644
--- a/repos/libports/src/lib/libc/socket_fs_plugin.cc
+++ b/repos/libports/src/lib/libc/socket_fs_plugin.cc
@@ -315,7 +315,7 @@ struct Libc::Socket_fs::Plugin : Libc::Plugin
 	int close(File_descriptor *) override;
 	bool poll(File_descriptor &fd, struct pollfd &pfd) override;
 	int select(int, fd_set *, fd_set *, fd_set *, timeval *) override;
-	int ioctl(File_descriptor *, int, char *) override;
+	int ioctl(File_descriptor *, unsigned long, char *) override;
 };
 
 
@@ -1275,7 +1275,7 @@ int Socket_fs::Plugin::close(File_descriptor *fd)
 }
 
 
-int Socket_fs::Plugin::ioctl(File_descriptor *, int request, char*)
+int Socket_fs::Plugin::ioctl(File_descriptor *, unsigned long request, char*)
 {
 	if (request == FIONREAD) {
 		/*
diff --git a/repos/libports/src/lib/libc/vfs_plugin.cc b/repos/libports/src/lib/libc/vfs_plugin.cc
index 811f442bf9..e37216c9bb 100644
--- a/repos/libports/src/lib/libc/vfs_plugin.cc
+++ b/repos/libports/src/lib/libc/vfs_plugin.cc
@@ -1061,7 +1061,7 @@ ssize_t Libc::Vfs_plugin::getdirentries(File_descriptor *fd, char *buf,
 }
 
 
-int Libc::Vfs_plugin::ioctl(File_descriptor *fd, int request, char *argp)
+int Libc::Vfs_plugin::ioctl(File_descriptor *fd, unsigned long request, char *argp)
 {
 	bool handled = false;
 
@@ -1114,7 +1114,7 @@ int Libc::Vfs_plugin::ioctl(File_descriptor *fd, int request, char *argp)
  * XXX Remove this method once all ioctl operations are supported via
  *     regular VFS file accesses.
  */
-int Libc::Vfs_plugin::_legacy_ioctl(File_descriptor *fd, int request, char *argp)
+int Libc::Vfs_plugin::_legacy_ioctl(File_descriptor *fd, unsigned long request, char *argp)
 {
 	using ::off_t;