diff --git a/libavcodec/flicvideo.c b/libavcodec/flicvideo.c
index c0e1e16bcd..99868f3ba3 100644
--- a/libavcodec/flicvideo.c
+++ b/libavcodec/flicvideo.c
@@ -175,7 +175,7 @@ static int flic_decode_frame_8BPP(AVCodecContext *avctx,
     int lines;
     int compressed_lines;
     int starting_line;
-    signed short line_packets;
+    int line_packets;
     int y_ptr;
     int byte_run;
     int pixel_skip;
@@ -274,7 +274,7 @@ static int flic_decode_frame_8BPP(AVCodecContext *avctx,
                     break;
                 if (y_ptr > pixel_limit)
                     return AVERROR_INVALIDDATA;
-                line_packets = bytestream2_get_le16(&g2);
+                line_packets = sign_extend(bytestream2_get_le16(&g2), 16);
                 if ((line_packets & 0xC000) == 0xC000) {
                     // line skip opcode
                     line_packets = -line_packets;
@@ -508,7 +508,7 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx,
 
     int lines;
     int compressed_lines;
-    signed short line_packets;
+    int line_packets;
     int y_ptr;
     int byte_run;
     int pixel_skip;
@@ -572,7 +572,7 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx,
                     break;
                 if (y_ptr > pixel_limit)
                     return AVERROR_INVALIDDATA;
-                line_packets = bytestream2_get_le16(&g2);
+                line_packets = sign_extend(bytestream2_get_le16(&g2), 16);
                 if (line_packets < 0) {
                     line_packets = -line_packets;
                     if (line_packets > s->avctx->height)
@@ -806,7 +806,7 @@ static int flic_decode_frame_24BPP(AVCodecContext *avctx,
 
     int lines;
     int compressed_lines;
-    signed short line_packets;
+    int line_packets;
     int y_ptr;
     int byte_run;
     int pixel_skip;
@@ -870,7 +870,7 @@ static int flic_decode_frame_24BPP(AVCodecContext *avctx,
                     break;
                 if (y_ptr > pixel_limit)
                     return AVERROR_INVALIDDATA;
-                line_packets = bytestream2_get_le16(&g2);
+                line_packets = sign_extend(bytestream2_get_le16(&g2), 16);
                 if (line_packets < 0) {
                     line_packets = -line_packets;
                     if (line_packets > s->avctx->height)