diff --git a/libc/src/stdio.cpp b/libc/src/stdio.cpp
index cef9bd27..0112746b 100644
--- a/libc/src/stdio.cpp
+++ b/libc/src/stdio.cpp
@@ -413,9 +413,3 @@ extern "C"
         return f;
     }
 }
-
-void debug_log_impl(const char* format, va_list ap)
-{
-    vfprintf(stderr, format, ap);
-    fputc('\n', stderr);
-}
diff --git a/libc/src/sys/mman.cpp b/libc/src/sys/mman.cpp
index 2ac4f3cc..ca38884b 100644
--- a/libc/src/sys/mman.cpp
+++ b/libc/src/sys/mman.cpp
@@ -18,17 +18,3 @@ extern "C"
         __errno_return(rc, int);
     }
 }
-
-Result<void*> allocate_pages_impl(usize count)
-{
-    long rc = syscall(SYS_mmap, nullptr, count * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS);
-    if (rc < 0) { return err((int)-rc); }
-    return (void*)rc;
-}
-
-Result<void> release_pages_impl(void* address, usize count)
-{
-    long rc = syscall(SYS_munmap, address, count * PAGE_SIZE);
-    if (rc < 0) { return err((int)-rc); }
-    return {};
-}
diff --git a/libluna/CMakeLists.txt b/libluna/CMakeLists.txt
index 3d1f3cee..e0bac9cf 100644
--- a/libluna/CMakeLists.txt
+++ b/libluna/CMakeLists.txt
@@ -29,8 +29,8 @@ set(FREESTANDING_SOURCES
 
 set(SOURCES
     ${FREESTANDING_SOURCES}
-    src/Check.cpp
     src/CppABI.cpp
+    src/ImplPOSIX.cpp
 )
 
 add_library(luna-freestanding ${FREESTANDING_SOURCES})
diff --git a/libluna/src/Check.cpp b/libluna/src/Check.cpp
deleted file mode 100644
index edd1df74..00000000
--- a/libluna/src/Check.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-#include <luna/Attributes.h>
-#include <luna/SourceLocation.h>
-
-#include <stdio.h>
-#include <stdlib.h>
-
-_weak [[noreturn]] bool __check_failed(SourceLocation location, const char* expr)
-{
-    fprintf(stderr, "Check failed at %s:%d in %s: %s\n", location.file(), location.line(), location.function(), expr);
-    abort();
-}
diff --git a/libluna/src/ImplPOSIX.cpp b/libluna/src/ImplPOSIX.cpp
new file mode 100644
index 00000000..ba799a32
--- /dev/null
+++ b/libluna/src/ImplPOSIX.cpp
@@ -0,0 +1,36 @@
+/* POSIX userspace implementation of libluna hooks. */
+
+#include <luna/Attributes.h>
+#include <luna/Result.h>
+#include <luna/SourceLocation.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+
+_weak [[noreturn]] bool __check_failed(SourceLocation location, const char* expr)
+{
+    fprintf(stderr, "Check failed at %s:%d in %s: %s\n", location.file(), location.line(), location.function(), expr);
+    abort();
+}
+
+void debug_log_impl(const char* format, va_list ap)
+{
+    vfprintf(stderr, format, ap);
+    fputc('\n', stderr);
+}
+
+Result<void*> allocate_pages_impl(usize count)
+{
+    void* rc = mmap(nullptr, count * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    if (rc == MAP_FAILED) { return err(errno); }
+    return rc;
+}
+
+Result<void> release_pages_impl(void* address, usize count)
+{
+    int rc = munmap(address, count * PAGE_SIZE);
+    if (rc < 0) { return err(errno); }
+    return {};
+}