diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 87218d4..c57f398 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -881,25 +881,8 @@
     o->auth_token_generate = false;
 
     /* Set default --tmp-dir */
-#ifdef _WIN32
-    /* On Windows, find temp dir via environment variables */
-    o->tmp_dir = win_get_tempdir();
+    o->tmp_dir = platform_get_tmp_dir();
 
-    if (!o->tmp_dir)
-    {
-        /* Error out if we can't find a valid temporary directory, which should
-         * be very unlikely. */
-        msg(M_USAGE, "Could not find a suitable temporary directory."
-                     " (GetTempPath() failed).  Consider using --tmp-dir");
-    }
-#else  /* ifdef _WIN32 */
-    /* Non-windows platforms use $TMPDIR, and if not set, default to '/tmp' */
-    o->tmp_dir = getenv("TMPDIR");
-    if (!o->tmp_dir)
-    {
-        o->tmp_dir = "/tmp";
-    }
-#endif /* _WIN32 */
     o->allow_recursive_routing = false;
 
 #ifndef ENABLE_DCO
diff --git a/src/openvpn/platform.c b/src/openvpn/platform.c
index 85b6408..6c766c2 100644
--- a/src/openvpn/platform.c
+++ b/src/openvpn/platform.c
@@ -584,6 +584,34 @@
     return NULL;
 }
 
+const char *
+platform_get_tmp_dir(void)
+{
+    const char *ret;
+#ifdef _WIN32
+    /* On Windows, find temp dir via environment variables */
+    ret = win_get_tempdir();
+
+    if (!ret)
+    {
+        /* Error out if we can't find a valid temporary directory, which should
+         * be very unlikely. */
+        msg(M_USAGE, "Could not find a suitable temporary directory."
+                     " (GetTempPath() failed).  Consider using --tmp-dir");
+    }
+#else
+    /* Non-windows platforms use $TMPDIR, and if not set, default to '/tmp' */
+    ret = getenv("TMPDIR");
+    if (!ret)
+    {
+        ret = "/tmp";
+    }
+#endif
+
+    return ret;
+}
+
+
 /*
  * Put a directory and filename together.
  */
diff --git a/src/openvpn/platform.h b/src/openvpn/platform.h
index 8e7ab7e..784427bb 100644
--- a/src/openvpn/platform.h
+++ b/src/openvpn/platform.h
@@ -128,6 +128,13 @@
 const char *platform_create_temp_file(const char *directory, const char *prefix,
                                       struct gc_arena *gc);
 
+/**
+ * Get a directory for temporary files
+ *
+ * @return path to a directory
+ */
+const char *platform_get_tmp_dir(void);
+
 /** Put a directory and filename together. */
 const char *platform_gen_path(const char *directory, const char *filename, struct gc_arena *gc);
 
diff --git a/tests/unit_tests/openvpn/test_ssl.c b/tests/unit_tests/openvpn/test_ssl.c
index 0e9cecf..065c7e3f 100644
--- a/tests/unit_tests/openvpn/test_ssl.c
+++ b/tests/unit_tests/openvpn/test_ssl.c
@@ -115,19 +115,6 @@
     "-----END PRIVATE KEY-----\n";
 
 
-static const char *
-get_tmp_dir(void)
-{
-    const char *ret;
-#ifdef _WIN32
-    ret = win_get_tempdir();
-#else
-    ret = "/tmp";
-#endif
-    assert_non_null(ret);
-    return ret;
-}
-
 static struct
 {
     struct gc_arena gc;
@@ -140,8 +127,8 @@
 {
     (void)state;
     global_state.gc = gc_new();
-    global_state.certfile = platform_create_temp_file(get_tmp_dir(), "cert", &global_state.gc);
-    global_state.keyfile = platform_create_temp_file(get_tmp_dir(), "key", &global_state.gc);
+    global_state.certfile = platform_create_temp_file(platform_get_tmp_dir(), "cert", &global_state.gc);
+    global_state.keyfile = platform_create_temp_file(platform_get_tmp_dir(), "key", &global_state.gc);
 
     int certfd = open(global_state.certfile, O_RDWR);
     int keyfd = open(global_state.keyfile, O_RDWR);
@@ -188,7 +175,7 @@
     cert = ctx.crt_chain;
 #endif
 
-    const char *tmpfile = platform_create_temp_file(get_tmp_dir(), "ut_pem", &gc);
+    const char *tmpfile = platform_create_temp_file(platform_get_tmp_dir(), "ut_pem", &gc);
     backend_x509_write_pem(cert, tmpfile);
 
     struct buffer exported_pem = buffer_read_from_file(tmpfile, &gc);
diff --git a/tests/unit_tests/openvpn/test_tls_crypt.c b/tests/unit_tests/openvpn/test_tls_crypt.c
index 1d8ac25..a2987c6 100644
--- a/tests/unit_tests/openvpn/test_tls_crypt.c
+++ b/tests/unit_tests/openvpn/test_tls_crypt.c
@@ -720,7 +720,7 @@
         tls_options.tls_crypt_v2_verify_script = "/bin/true";
     }
 
-    tls_options.tmp_dir = "/tmp";
+    tls_options.tmp_dir = platform_get_tmp_dir();
 
     /* Since we override rand_bytes the tmpfile name is non-random as well.
      * Build the expected name via the same code path as