diff --git a/repos/libports/ports/gcov.hash b/repos/libports/ports/gcov.hash
index 414a014f22..a9a3085fc4 100644
--- a/repos/libports/ports/gcov.hash
+++ b/repos/libports/ports/gcov.hash
@@ -1 +1 @@
-270978954f87ac494b04c2cc1c15c23102f07406
+f0518e32e26d8286b84789e661c4999e01d8b569
diff --git a/repos/libports/src/lib/gcov/libc/libc.cc b/repos/libports/src/lib/gcov/libc/libc.cc
index e91436d05c..266f14cdc1 100644
--- a/repos/libports/src/lib/gcov/libc/libc.cc
+++ b/repos/libports/src/lib/gcov/libc/libc.cc
@@ -212,13 +212,6 @@ extern "C" void *malloc(size_t size)
 }
 
 
-extern "C" void setbuf(FILE *stream, char *buf)
-{
-	if (buf)
-		Genode::error("setbuf(", (void*)buf, "): not implemented");
-}
-
-
 extern "C" char *strcpy(char *dest, const char *src)
 {
 	return Genode::strncpy(dest, src, Genode::strlen(src) + 1);
diff --git a/repos/libports/src/lib/gcov/patches/setbuf.patch b/repos/libports/src/lib/gcov/patches/setbuf.patch
new file mode 100644
index 0000000000..c572f813b1
--- /dev/null
+++ b/repos/libports/src/lib/gcov/patches/setbuf.patch
@@ -0,0 +1,23 @@
+open files in buffered mode
+
+From: Christian Prochaska <christian.prochaska@genode-labs.com>
+
+
+---
+ gcc/gcov-io.c |    2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/gcc/gcov-io.c b/gcc/gcov-io.c
+index 17fcae0..269196a 100644
+--- a/gcc/gcov-io.c
++++ b/gcc/gcov-io.c
+@@ -217,7 +217,9 @@ gcov_open (const char *name, int mode)
+     return 0;
+ #endif
+ 
++#if 0
+   setbuf (gcov_var.file, (char *)0);
++#endif
+ 
+   return 1;
+ }