diff --git a/packages/genodelabs/libc.patch b/packages/genodelabs/libc.patch
index 0dce9c2..4d2c090 100644
--- a/packages/genodelabs/libc.patch
+++ b/packages/genodelabs/libc.patch
@@ -38,3 +38,29 @@ index 8e75e59589..2bb98b1456 100644
  
  SRC_C = $(filter-out $(FILTER_OUT),$(notdir $(wildcard $(LIBC_LOCALE_DIR)/*.c)))
  
+commit 81fc78f8e0ac66a7275e149f7f7fdc5f4f1f2979
+Author: Emery Hemingway <ehmry@posteo.net>
+Date:   Wed May 27 16:35:16 2020 +0530
+
+    libc: add mlock and munlock dummies
+
+diff --git a/repos/libports/src/lib/libc/dummies.cc b/repos/libports/src/lib/libc/dummies.cc
+index 37c2c83f89..bc2f15a90a 100644
+--- a/repos/libports/src/lib/libc/dummies.cc
++++ b/repos/libports/src/lib/libc/dummies.cc
+@@ -221,5 +221,15 @@ int __attribute__((weak)) madvise(void *addr, size_t length, int advice)
+ 
+ const struct res_sym __p_type_syms[] = { };
+ 
++#define DUMMY_EPERM(ret_type, ret_val, name, args) __attribute__((weak)) \
++ret_type name args \
++{ \
++	errno = EPERM; \
++	return ret_val; \
++}
++
++DUMMY_EPERM(int, -1,   mlock, (const void *, size_t));
++DUMMY_EPERM(int, -1, munlock, (const void *, size_t));
++
+ } /* extern "C" */
+