diff --git a/src/hostapi/coreaudio/pa_mac_core.c b/src/hostapi/coreaudio/pa_mac_core.c
index 1cef082..14632d9 100644
--- a/src/hostapi/coreaudio/pa_mac_core.c
+++ b/src/hostapi/coreaudio/pa_mac_core.c
@@ -661,7 +661,7 @@ static PaError InitializeDeviceInfo( PaMacAUHAL *auhalHostApi,
 
     VVDBUG(("InitializeDeviceInfo(): macCoreDeviceId=%ld\n", macCoreDeviceId));
 
-    memset(deviceInfo, 0, sizeof(deviceInfo));
+    memset(deviceInfo, 0, sizeof(PaDeviceInfo));
 
     deviceInfo->structVersion = 2;
     deviceInfo->hostApi = hostApiIndex;