diff --git a/spa/plugins/alsa/acp/compat.h b/spa/plugins/alsa/acp/compat.h
index f7592e1a6..0f7b959df 100644
--- a/spa/plugins/alsa/acp/compat.h
+++ b/spa/plugins/alsa/acp/compat.h
@@ -429,9 +429,9 @@ static PA_PRINTF_FUNC(1,0) inline char *pa_vsprintf_malloc(const char *fmt, va_l
 
 #define pa_fopen_cloexec(f,m)	fopen(f,m"e")
 
-static inline char *pa_path_get_filename(const char *p)
+static inline const char *pa_path_get_filename(const char *p)
 {
-    char *fn;
+    const char *fn;
     if (!p)
         return NULL;
     if ((fn = strrchr(p, PA_PATH_SEP_CHAR)))