diff --git a/src/libopensc/reader-pcsc.c b/src/libopensc/reader-pcsc.c
index 50d50afe..4a5e2391 100644
--- a/src/libopensc/reader-pcsc.c
+++ b/src/libopensc/reader-pcsc.c
@@ -1098,7 +1098,7 @@ static int pcsc_detect_readers(sc_context_t *ctx)
 		else {
 			rv = gpriv->SCardListReaders(gpriv->pcsc_ctx, NULL, NULL,
 					      (LPDWORD) &reader_buf_size);
-			if (rv == SCARD_E_NO_SERVICE) {
+			if (rv == (LONG)SCARD_E_NO_SERVICE) {
 				gpriv->SCardReleaseContext(gpriv->pcsc_ctx);
 				gpriv->pcsc_ctx = -1;
 				gpriv->pcsc_wait_ctx = -1;