diff --git a/src/video/vid_s3.c b/src/video/vid_s3.c
index 11321dae1..fae21a279 100644
--- a/src/video/vid_s3.c
+++ b/src/video/vid_s3.c
@@ -2178,7 +2178,7 @@ s3_out(uint16_t addr, uint8_t val, void *p)
 				return;
 			} else if ((svga->seqaddr == 0x0d) && (svga->seqregs[0x08] == 0x06)) {
 				svga->seqregs[svga->seqaddr] = val;
-				svga->dpms = ((s3->chip >= S3_VISION964) && (svga->seqregs[0x0d] & 0xf0)) || (svga->crtc[0x56] & ((s3->chip >= S3_TRIO32) ? 0x06 : 0x20));
+				svga->dpms = ((s3->chip >= S3_VISION964) && (svga->seqregs[0x0d] & 0x50)) || (svga->crtc[0x56] & ((s3->chip >= S3_TRIO32) ? 0x06 : 0x20));
 				svga_recalctimings(svga);
 				return;
 			}
@@ -2387,7 +2387,7 @@ s3_out(uint16_t addr, uint8_t val, void *p)
 			break;
 
                         case 0x56:
-                        svga->dpms = ((s3->chip >= S3_VISION964) && (svga->seqregs[0x0d] & 0xf0)) || (svga->crtc[0x56] & ((s3->chip >= S3_TRIO32) ? 0x06 : 0x20));
+                        svga->dpms = ((s3->chip >= S3_VISION964) && (svga->seqregs[0x0d] & 0x50)) || (svga->crtc[0x56] & ((s3->chip >= S3_TRIO32) ? 0x06 : 0x20));
                         old = ~val; /* force recalc */
                         break;
 
diff --git a/src/video/vid_s3_virge.c b/src/video/vid_s3_virge.c
index 0752499b3..4b37eda62 100644
--- a/src/video/vid_s3_virge.c
+++ b/src/video/vid_s3_virge.c
@@ -433,7 +433,7 @@ static void s3_virge_out(uint16_t addr, uint8_t val, void *p)
 			return;
 		} else if ((svga->seqaddr == 0x0d) && (svga->seqregs[0x08] == 0x06)) {
 			svga->seqregs[svga->seqaddr] = val;
-			svga->dpms = (svga->seqregs[0x0d] & 0xf0) || (svga->crtc[0x56] & 0x06);
+			svga->dpms = (svga->seqregs[0x0d] & 0x50) || (svga->crtc[0x56] & 0x06);
 			svga_recalctimings(svga);
 			return;
 		}
@@ -553,7 +553,7 @@ static void s3_virge_out(uint16_t addr, uint8_t val, void *p)
                         break;
 
                         case 0x56:
-                        svga->dpms = (svga->seqregs[0x0d] & 0xf0) || (svga->crtc[0x56] & 0x06);
+                        svga->dpms = (svga->seqregs[0x0d] & 0x50) || (svga->crtc[0x56] & 0x06);
                         old = ~val; /* force recalc */
                         break;