diff --git a/dlls/msacm32/pcmconverter.c b/dlls/msacm32/pcmconverter.c
index cf92d93..fc255f1 100644
--- a/dlls/msacm32/pcmconverter.c
+++ b/dlls/msacm32/pcmconverter.c
@@ -857,11 +857,18 @@ static	LRESULT	PCM_FormatSuggest(PACMDRVFORMATSUGGEST adfs)
     }
     if (!(adfs->fdwSuggest & ACM_FORMATSUGGESTF_WFORMATTAG)) {
 	if (adfs->pwfxSrc->wFormatTag != WAVE_FORMAT_PCM) {
-            WARN("not possible\n");
+            WARN("source format 0x%x not supported\n", adfs->pwfxSrc->wFormatTag);
             return ACMERR_NOTPOSSIBLE;
         }
 	adfs->pwfxDst->wFormatTag = adfs->pwfxSrc->wFormatTag;
     }
+    else
+    {
+	if (adfs->pwfxDst->wFormatTag != WAVE_FORMAT_PCM) {
+            WARN("destination format 0x%x not supported\n", adfs->pwfxDst->wFormatTag);
+            return ACMERR_NOTPOSSIBLE;
+        }
+    }
     /* check if result is ok */
     if (PCM_GetFormatIndex(adfs->pwfxDst) == 0xFFFFFFFF) {
         WARN("not possible\n");