diff --git a/psycopg/config.h b/psycopg/config.h
index 551cfe4..90d14b4 100644
--- a/psycopg/config.h
+++ b/psycopg/config.h
@@ -41,10 +41,11 @@ extern HIDDEN int psycopg_debug_enabled;
 #if defined( __GNUC__) && !defined(__APPLE__)
 #ifdef PSYCOPG_DEBUG
 #include <sys/types.h>
+#include <sys/syscall.h>
 #include <unistd.h>
 #define Dprintf(fmt, args...) \
     if (!psycopg_debug_enabled) ; else \
-        fprintf(stderr, "[%d] " fmt "\n", (int) getpid() , ## args)
+        fprintf(stderr, "[%d %ld] " fmt "\n", (int) getpid(), (long) syscall(SYS_gettid), ## args)
 #else
 #define Dprintf(fmt, args...)
 #endif
diff --git a/psycopg/psycopgmodule.c b/psycopg/psycopgmodule.c
index c5daefd..95057d0 100644
--- a/psycopg/psycopgmodule.c
+++ b/psycopg/psycopgmodule.c
@@ -842,6 +842,7 @@ INIT_MODULE(_psycopg)(void)
 #endif
 
     Dprintf("initpsycopg: initializing psycopg %s", PSYCOPG_VERSION);
+    Dprintf("is libpq thread safe? %d", PQisthreadsafe());
 
     /* initialize all the new types and then the module */
     Py_TYPE(&connectionType) = &PyType_Type;