diff --git a/hw/gus.c b/hw/gus.c
index fb129cd49d..860a47c357 100644
--- a/hw/gus.c
+++ b/hw/gus.c
@@ -42,9 +42,9 @@
 #endif
 
 #define IO_READ_PROTO(name) \
-    uint32_t name (void *opaque, uint32_t nport)
+    static uint32_t name (void *opaque, uint32_t nport)
 #define IO_WRITE_PROTO(name) \
-    void name (void *opaque, uint32_t nport, uint32_t val)
+    static void name (void *opaque, uint32_t nport, uint32_t val)
 
 static struct {
     int port;
@@ -195,7 +195,7 @@ void GUS_dmarequest (GUSEmuState *der)
     DMA_hold_DREQ (der->gusdma);
 }
 
-int GUS_read_DMA (void *opaque, int nchan, int dma_pos, int dma_len)
+static int GUS_read_DMA (void *opaque, int nchan, int dma_pos, int dma_len)
 {
     GUSState *s = opaque;
     char tmpbuf[4096];