diff --git a/libavcodec/interplayvideo.c b/libavcodec/interplayvideo.c
index cdbea2edd1..50db2e95da 100644
--- a/libavcodec/interplayvideo.c
+++ b/libavcodec/interplayvideo.c
@@ -493,18 +493,19 @@ static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s)
 static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s)
 {
     int y;
-    unsigned char P;
+    unsigned char P[2];
 
     /* 4-color block encoding: each 4x4 block is a different color */
     CHECK_STREAM_PTR(4);
 
-    for (y = 0; y < 16; y++) {
-        if (!(y & 3)) // start of block
-            P = *s->stream_ptr++;
-        memset(s->pixel_ptr, P, 4);
+    for (y = 0; y < 8; y++) {
+        if (!(y & 3)) {
+            P[0] = *s->stream_ptr++;
+            P[1] = *s->stream_ptr++;
+        }
+        memset(s->pixel_ptr,     P[0], 4);
+        memset(s->pixel_ptr + 4, P[1], 4);
         s->pixel_ptr += s->stride;
-        // switch to right half
-        if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
     }
 
     /* report success */