diff --git a/src/libopensc/ctx.c b/src/libopensc/ctx.c
index 1b267095..30b5c061 100644
--- a/src/libopensc/ctx.c
+++ b/src/libopensc/ctx.c
@@ -545,7 +545,7 @@ static void process_config_file(sc_context_t *ctx, struct _sc_ctx_options *opts)
 
 int sc_ctx_detect_readers(sc_context_t *ctx)
 {
-	int r;
+	int r = 0;
 	const struct sc_reader_driver *drv = ctx->reader_driver;
 
 	sc_mutex_lock(ctx, ctx->mutex);