diff --git a/common/sysutils.c b/common/sysutils.c
index 01f654250..5f54ae155 100644
--- a/common/sysutils.c
+++ b/common/sysutils.c
@@ -779,8 +779,12 @@ gnupg_allow_set_foregound_window (pid_t pid)
               "gnupg_allow_set_foregound_window", (unsigned long)pid);
 #if defined(HAVE_W32_SYSTEM) && !defined(HAVE_W32CE_SYSTEM)
   else if (!AllowSetForegroundWindow ((pid_t)pid == (pid_t)(-1)?ASFW_ANY:pid))
-    log_info ("AllowSetForegroundWindow(%lu) failed: %s\n",
-               (unsigned long)pid, w32_strerror (-1));
+    {
+      char *flags = getenv ("GNUPG_EXEC_DEBUG_FLAGS");
+      if (flags && (atoi (flags) & 2))
+        log_info ("AllowSetForegroundWindow(%lu) failed: %s\n",
+                  (unsigned long)pid, w32_strerror (-1));
+    }
 #endif
 }
 
diff --git a/doc/gpg.texi b/doc/gpg.texi
index f51c3d9ec..39c996bd9 100644
--- a/doc/gpg.texi
+++ b/doc/gpg.texi
@@ -3818,6 +3818,12 @@ Operation is further controlled by a few environment variables:
   under operating systems without proper support to figure out the
   name of a process' text file.
 
+  @item GNUPG_EXEC_DEBUG_FLAGS
+  @efindex GNUPG_EXEC_DEBUG_FLAGS
+  This variable allows to enable diagnostics for process management.
+  A numeric decimal value is expected.  Bit 0 enables general
+  diagnostics, bit 1 enables certain warnings on Windows.
+
 @end table
 
 When calling the gpg-agent component @command{@gpgname} sends a set of