diff --git a/glib/gspawn.c b/glib/gspawn.c
index 0b9473022..c8e0ca806 100644
--- a/glib/gspawn.c
+++ b/glib/gspawn.c
@@ -1753,8 +1753,10 @@ fork_exec_with_fds (gboolean              intermediate_child,
   gint status;
   const gchar *chosen_search_path;
   gchar *search_path_buffer = NULL;
+  gchar *search_path_buffer_heap = NULL;
   gsize search_path_buffer_len = 0;
   gchar **argv_buffer = NULL;
+  gchar **argv_buffer_heap = NULL;
   gsize argv_buffer_len = 0;
 
 #ifdef POSIX_SPAWN_AVAILABLE
@@ -1848,7 +1850,17 @@ fork_exec_with_fds (gboolean              intermediate_child,
   if (chosen_search_path != NULL)
     {
       search_path_buffer_len = strlen (chosen_search_path) + strlen (argv[0]) + 2;
-      search_path_buffer = g_malloc (search_path_buffer_len);
+      if (search_path_buffer_len < 4000)
+        {
+          /* Prefer small stack allocations to avoid valgrind leak warnings
+           * in forked child. The 4000B cutoff is arbitrary. */
+          search_path_buffer = g_alloca (search_path_buffer_len);
+        }
+      else
+        {
+          search_path_buffer_heap = g_malloc (search_path_buffer_len);
+          search_path_buffer = search_path_buffer_heap;
+        }
     }
 
   if (search_path || search_path_from_envp)
@@ -1860,12 +1872,22 @@ fork_exec_with_fds (gboolean              intermediate_child,
    * script_execute() has to be called later on, it can build a wrapper argv
    * array in this buffer. */
   argv_buffer_len = g_strv_length (argv) + 2;
-  argv_buffer = g_new (gchar *, argv_buffer_len);
+  if (argv_buffer_len < 4000 / sizeof (gchar *))
+    {
+      /* Prefer small stack allocations to avoid valgrind leak warnings
+       * in forked child. The 4000B cutoff is arbitrary. */
+      argv_buffer = g_newa (gchar *, argv_buffer_len);
+    }
+  else
+    {
+      argv_buffer_heap = g_new (gchar *, argv_buffer_len);
+      argv_buffer = argv_buffer_heap;
+    }
 
   if (!g_unix_open_pipe (child_err_report_pipe, pipe_flags, error))
     {
-      g_free (search_path_buffer);
-      g_free (argv_buffer);
+      g_free (search_path_buffer_heap);
+      g_free (argv_buffer_heap);
       return FALSE;
     }
 
@@ -2112,8 +2134,8 @@ fork_exec_with_fds (gboolean              intermediate_child,
       close_and_invalidate (&child_err_report_pipe[0]);
       close_and_invalidate (&child_pid_report_pipe[0]);
 
-      g_free (search_path_buffer);
-      g_free (argv_buffer);
+      g_free (search_path_buffer_heap);
+      g_free (argv_buffer_heap);
 
       if (child_pid)
         *child_pid = pid;
@@ -2147,8 +2169,8 @@ fork_exec_with_fds (gboolean              intermediate_child,
   close_and_invalidate (&child_pid_report_pipe[0]);
   close_and_invalidate (&child_pid_report_pipe[1]);
 
-  g_free (search_path_buffer);
-  g_free (argv_buffer);
+  g_free (search_path_buffer_heap);
+  g_free (argv_buffer_heap);
 
   return FALSE;
 }