diff --git a/gum/backend-linux/gumprocess-linux.c b/gum/backend-linux/gumprocess-linux.c
index 7b1cd7b4f..25067f952 100644
--- a/gum/backend-linux/gumprocess-linux.c
+++ b/gum/backend-linux/gumprocess-linux.c
@@ -48,9 +48,8 @@
 #ifdef HAVE_SYS_USER_H
 # include <sys/user.h>
 #endif
-#ifdef HAVE_LINUX
+#include <sys/time.h>
 #include <sys/resource.h>
-#endif
 
 #define GUM_PAGE_START(value, page_size) \
     (GUM_ADDRESS (value) & ~GUM_ADDRESS (page_size - 1))
@@ -90,6 +89,9 @@
 #ifndef NT_PRSTATUS
 # define NT_PRSTATUS 1
 #endif
+#ifndef RUSAGE_THREAD
+# define RUSAGE_THREAD 1
+#endif
 
 #define GUM_TEMP_FAILURE_RETRY(expression) \
     ({ \
diff --git a/gum/backend-windows/gumprocess-windows.c b/gum/backend-windows/gumprocess-windows.c
index a4197ef4d..c5d926c33 100644
--- a/gum/backend-windows/gumprocess-windows.c
+++ b/gum/backend-windows/gumprocess-windows.c
@@ -643,7 +643,7 @@ gum_thread_resume (GumThreadId thread_id,
 guint64
 gum_thead_get_user_time (void)
 {
-  static gboolean initialized = false;
+  static gboolean initialized = FALSE;
   static GetThreadTimesFunc get_thread_times = NULL;
 
   HMODULE mod;
@@ -668,7 +668,7 @@ gum_thead_get_user_time (void)
   if (!get_thread_times (GetCurrentThread (), NULL, NULL, NULL, &userTime))
     return 0;
 
-  result = ((guint64) userTime.dwHighDateTime) << 32 + userTime.dwLowDateTime;
+  result = (((guint64) userTime.dwHighDateTime) << 32) + userTime.dwLowDateTime;
 
   /* Timings on Windows are to 100-nanosecond granularity. Convert to u-secs */
   return result / 10;
diff --git a/tests/gumjs/script.c b/tests/gumjs/script.c
index 4d2fc5c95..c5eacfe2c 100644
--- a/tests/gumjs/script.c
+++ b/tests/gumjs/script.c
@@ -5194,22 +5194,25 @@ TESTCASE (process_threads_get_user_time)
 
 TESTCASE (process_threads_get_user_time_other_thread)
 {
+#if defined (HAVE_LINUX) && !defined (HAVE_PTHREAD_SETNAME_NP)
+  g_print ("<skipping, libc is too old> ");
+#else
   GumNamedSleeperContext ctx;
   GThread * thread;
   double user_time_a = 0, user_time_b = 0;
 
-#ifdef HAVE_LINUX
+# ifdef HAVE_LINUX
   if (!check_exception_handling_testable ())
     return;
-#endif
+# endif
 
-#ifdef HAVE_MIPS
+# ifdef HAVE_MIPS
   if (!g_test_slow ())
   {
     g_print ("<skipping, run in slow mode> ");
     return;
   }
-#endif
+# endif
 
   ctx.controller_messages = g_async_queue_new ();
   ctx.sleeper_messages = g_async_queue_new ();
@@ -5251,13 +5254,14 @@ TESTCASE (process_threads_get_user_time_other_thread)
   g_async_queue_unref (ctx.sleeper_messages);
   g_async_queue_unref (ctx.controller_messages);
 
-#if defined (HAVE_LINUX) || defined (HAVE_DARWIN) || defined (HAVE_FREEBSD) \
+# if defined (HAVE_LINUX) || defined (HAVE_DARWIN) || defined (HAVE_FREEBSD) \
     || defined (HAVE_WINDOWS)
     g_assert_true (user_time_a != 0);
     g_assert_true (user_time_b > user_time_a);
-#else
+# else
     g_assert_cmpuint (user_time_a, ==, 0);
     g_assert_cmpuint (user_time_b, ==, 0);
+# endif
 #endif
 }
 
@@ -5271,7 +5275,7 @@ user_time (gpointer data)
    * to GLib potentially having been prebuilt against an old libc. Therefore we
    * set the name manually using pthreads.
    */
-#ifdef HAVE_LINUX
+#if defined (HAVE_LINUX) && defined (HAVE_PTHREAD_SETNAME_NP)
   pthread_setname_np (pthread_self (), "user-time");
 #endif
 
@@ -5304,21 +5308,24 @@ do_work (void)
 
 TESTCASE (process_threads_find_busy_thread)
 {
+#if defined (HAVE_LINUX) && !defined (HAVE_PTHREAD_SETNAME_NP)
+  g_print ("<skipping, libc is too old> ");
+#else
   GumHotNamedSleeperContext ctx[NUM_THREADS];
   GThread * thread[NUM_THREADS];
 
-#ifdef HAVE_LINUX
+# ifdef HAVE_LINUX
   if (!check_exception_handling_testable ())
     return;
-#endif
+# endif
 
-#ifdef HAVE_MIPS
+# ifdef HAVE_MIPS
   if (!g_test_slow ())
   {
     g_print ("<skipping, run in slow mode> ");
     return;
   }
-#endif
+# endif
 
   guint rand = g_random_int_range (0, 10);
 
@@ -5362,9 +5369,10 @@ TESTCASE (process_threads_find_busy_thread)
     g_async_queue_unref (ctx[i].controller_messages);
   }
 
-#if defined (HAVE_LINUX) || defined (HAVE_DARWIN) || defined (HAVE_FREEBSD) \
+# if defined (HAVE_LINUX) || defined (HAVE_DARWIN) || defined (HAVE_FREEBSD) \
     || defined (HAVE_WINDOWS)
   EXPECT_SEND_MESSAGE_WITH ("%" G_GSIZE_MODIFIER "u", ctx[rand].id);
+# endif
 #endif
 }