diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index ea28822..3c2dcf2 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -964,10 +964,7 @@
 
   // create memfd
   int memfd = memfd_create("foobar", MFD_CLOEXEC);
-  if (memfd == -1 && errno == ENOSYS) {
-    return;
-  }
-
+  if (memfd == -1 && errno == ENOSYS) GTEST_SKIP() << "no memfd_create() in this kernel";
   ASSERT_TRUE(memfd != -1) << strerror(errno);
 
   // Check st.f_type is TMPFS_MAGIC for memfd
diff --git a/tests/fdtrack_test.cpp b/tests/fdtrack_test.cpp
index ff6d8c8..5988bc4 100644
--- a/tests/fdtrack_test.cpp
+++ b/tests/fdtrack_test.cpp
@@ -235,27 +235,22 @@
 
 FDTRACK_TEST(pidfd_open, ({
   int rc = pidfd_open(getpid(), 0);
-  if (rc == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_open not available";
-  }
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
+  ASSERT_NE(-1, rc) << strerror(errno);
   rc;
 }));
 
 FDTRACK_TEST(pidfd_getfd, ({
   android_fdtrack_set_enabled(false);
   int pidfd_self = pidfd_open(getpid(), 0);
-  if (pidfd_self == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_open not available";
-  }
+  if (pidfd_self == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
+  ASSERT_NE(-1, pidfd_self) << strerror(errno);
+
   android_fdtrack_set_enabled(true);
 
   int rc = pidfd_getfd(pidfd_self, STDIN_FILENO, 0);
-  if (rc == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_getfd not available";
-  }
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_getfd() in this kernel";
+  ASSERT_NE(-1, rc) << strerror(errno);
 
   android_fdtrack_set_enabled(false);
   close(pidfd_self);
diff --git a/tests/membarrier_test.cpp b/tests/membarrier_test.cpp
index 891488b..0cb7df4 100644
--- a/tests/membarrier_test.cpp
+++ b/tests/membarrier_test.cpp
@@ -30,7 +30,7 @@
   ~ScopedErrnoCleaner() { errno = 0; }
 };
 
-bool HasMembarrier(int membarrier_cmd) {
+static bool HasMembarrier(int membarrier_cmd) {
   ScopedErrnoCleaner errno_cleaner;
   int supported_cmds = syscall(__NR_membarrier, MEMBARRIER_CMD_QUERY, 0);
   return (supported_cmds > 0) && ((supported_cmds & membarrier_cmd) != 0);
@@ -39,11 +39,8 @@
 TEST(membarrier, query) {
   ScopedErrnoCleaner errno_cleaner;
   int supported = syscall(__NR_membarrier, MEMBARRIER_CMD_QUERY, 0);
-  if (errno == 0) {
-    ASSERT_TRUE(supported >= 0);
-  } else {
-    ASSERT_TRUE(errno == ENOSYS && supported == -1);
-  }
+  if (supported == -1 && errno == ENOSYS) GTEST_SKIP() << "no membarrier() in this kernel";
+  ASSERT_GE(supported, 0);
 }
 
 TEST(membarrier, global_barrier) {
diff --git a/tests/pidfd_test.cpp b/tests/pidfd_test.cpp
index e2e2046..c01b93f 100644
--- a/tests/pidfd_test.cpp
+++ b/tests/pidfd_test.cpp
@@ -45,10 +45,8 @@
   }
 
   unique_fd pidfd(pidfd_open(child, 0));
-  if (pidfd.get() == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_open not available";
-  }
+  if (pidfd.get() == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
+  ASSERT_NE(-1, pidfd.get()) << strerror(errno);
 
   siginfo_t siginfo;
   int rc = waitid(P_PIDFD, pidfd.get(), &siginfo, WEXITED);
@@ -66,16 +64,12 @@
   unique_fd r, w;
   ASSERT_TRUE(android::base::Pipe(&r, &w));
   unique_fd self(pidfd_open(getpid(), 0));
-  if (self.get() == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_open not available";
-  }
+  if (self.get() == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
+  ASSERT_NE(-1, self.get()) << strerror(errno);
 
   unique_fd dup(pidfd_getfd(self.get(), r.get(), 0));
-  if (dup.get() == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_getfd not available";
-  }
+  if (dup.get() == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_getfd() in this kernel";
+  ASSERT_NE(-1, dup.get()) << strerror(errno);
 
   ASSERT_NE(r.get(), dup.get());
   ASSERT_EQ(3, write(w.get(), "foo", 3));
@@ -88,15 +82,12 @@
 TEST_F(pidfd_DeathTest, pidfd_send_signal) {
 #if defined(__BIONIC__)
   unique_fd self(pidfd_open(getpid(), 0));
-  if (self.get() == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_open not available";
-  }
+  if (self.get() == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_open() in this kernel";
+  ASSERT_NE(-1, self.get()) << strerror(errno);
 
-  if (pidfd_send_signal(self.get(), 0, nullptr, 0) == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "pidfd_send_signal not available";
-  }
+  int rc = pidfd_send_signal(self.get(), 0, nullptr, 0);
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no pidfd_send_signal() in this kernel";
+  ASSERT_EQ(0, rc) << strerror(errno);
 
   ASSERT_EXIT(({
                 // gtest will fork a child off for ASSERT_EXIT: `self` refers to the parent.
diff --git a/tests/sys_epoll_test.cpp b/tests/sys_epoll_test.cpp
index abd928a..744f1c9 100644
--- a/tests/sys_epoll_test.cpp
+++ b/tests/sys_epoll_test.cpp
@@ -64,7 +64,7 @@
   epoll_event events[1] = {};
   timespec ts = {.tv_nsec = 500};
   int rc = epoll_pwait2(epoll_fd, events, 1, &ts, nullptr);
-  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2 in this kernel";
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2() in this kernel";
   ASSERT_EQ(0, rc) << strerror(errno);
 #else
   GTEST_SKIP() << "epoll_pwait2 is only in glibc 2.35+";
@@ -94,7 +94,7 @@
   sigemptyset(&ss2);
   sigaddset(&ss2, SIGPIPE);
   int rc = epoll_pwait2(epoll_fd, events, 1, &ts, &ss2);
-  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2 in this kernel";
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2() in this kernel";
   ASSERT_EQ(0, rc) << strerror(errno);
 #else
   GTEST_SKIP() << "epoll_pwait2 is only in glibc 2.35+";
@@ -112,7 +112,7 @@
   sigemptyset64(&ss2);
   sigaddset64(&ss2, SIGPIPE);
   int rc = epoll_pwait2_64(epoll_fd, events, 1, &ts, &ss2);
-  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2 in this kernel";
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2() in this kernel";
   ASSERT_EQ(0, rc) << strerror(errno);
 #else
   GTEST_SKIP() << "epoll_pwait2_64 is bionic-only";
diff --git a/tests/sys_mman_test.cpp b/tests/sys_mman_test.cpp
index 9421565..e785ff4 100644
--- a/tests/sys_mman_test.cpp
+++ b/tests/sys_mman_test.cpp
@@ -279,10 +279,9 @@
   // Is the MFD_CLOEXEC flag obeyed?
   errno = 0;
   int fd = memfd_create("doesn't matter", 0);
-  if (fd == -1) {
-    ASSERT_ERRNO(ENOSYS);
-    GTEST_SKIP() << "no memfd_create available";
-  }
+  if (fd == -1 && errno == ENOSYS) GTEST_SKIP() << "no memfd_create() in this kernel";
+  ASSERT_NE(-1, fd) << strerror(errno);
+
   int f = fcntl(fd, F_GETFD);
   ASSERT_NE(-1, f);
   ASSERT_FALSE(f & FD_CLOEXEC);
diff --git a/tests/sys_stat_test.cpp b/tests/sys_stat_test.cpp
index b00f6e2..126f469 100644
--- a/tests/sys_stat_test.cpp
+++ b/tests/sys_stat_test.cpp
@@ -109,9 +109,7 @@
 #if defined(HAVE_STATX)
   struct statx sx;
   int rc = statx(AT_FDCWD, "/proc/version", AT_STATX_SYNC_AS_STAT, STATX_ALL, &sx);
-  if (rc == -1 && errno == ENOSYS) {
-    GTEST_SKIP() << "statx returned ENOSYS";
-  }
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no statx() in this kernel";
   ASSERT_EQ(0, rc);
   struct stat64 sb;
   ASSERT_EQ(0, stat64("/proc/version", &sb));
diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index 74bd2f4..6a94507 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -1689,16 +1689,13 @@
   int fd = open("/proc/version", O_RDONLY);
   ASSERT_GE(fd, 0);
 
-  // Try to close the file descriptor (this requires a 5.9+ kernel)
-  if (close_range(fd, fd, 0) == 0) {
-    // we can't close it *again*
-    ASSERT_EQ(close(fd), -1);
-    ASSERT_ERRNO(EBADF);
-  } else {
-    ASSERT_ERRNO(ENOSYS);
-    // since close_range() failed, we can close it normally
-    ASSERT_EQ(close(fd), 0);
-  }
+  int rc = close_range(fd, fd, 0);
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no close_range() in this kernel";
+  ASSERT_EQ(0, rc) << strerror(errno);
+
+  // Check the fd is actually closed.
+  ASSERT_EQ(close(fd), -1);
+  ASSERT_ERRNO(EBADF);
 #endif  // __GLIBC__
 }