diff --git a/libavfilter/dnn/dnn_backend_tf.c b/libavfilter/dnn/dnn_backend_tf.c
index a921667424..9ceca5cea0 100644
--- a/libavfilter/dnn/dnn_backend_tf.c
+++ b/libavfilter/dnn/dnn_backend_tf.c
@@ -95,7 +95,7 @@ static TF_Tensor *allocate_input_tensor(const DNNData *input)
         break;
     case DNN_UINT8:
         dt = TF_UINT8;
-        size = sizeof(char);
+        size = 1;
         break;
     default:
         av_assert0(!"should not reach here");
diff --git a/libavfilter/vf_deshake.c b/libavfilter/vf_deshake.c
index b516ea2d59..28a541b94a 100644
--- a/libavfilter/vf_deshake.c
+++ b/libavfilter/vf_deshake.c
@@ -354,7 +354,7 @@ static av_cold int init(AVFilterContext *ctx)
     if (deshake->filename)
         deshake->fp = fopen(deshake->filename, "w");
     if (deshake->fp)
-        fwrite("Ori x, Avg x, Fin x, Ori y, Avg y, Fin y, Ori angle, Avg angle, Fin angle, Ori zoom, Avg zoom, Fin zoom\n", sizeof(char), 104, deshake->fp);
+        fwrite("Ori x, Avg x, Fin x, Ori y, Avg y, Fin y, Ori angle, Avg angle, Fin angle, Ori zoom, Avg zoom, Fin zoom\n", 1, 104, deshake->fp);
 
     // Quadword align left edge of box for MMX code, adjust width if necessary
     // to keep right margin
@@ -485,7 +485,7 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
     // Write statistics to file
     if (deshake->fp) {
         snprintf(tmp, 256, "%f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f\n", orig.vec.x, deshake->avg.vec.x, t.vec.x, orig.vec.y, deshake->avg.vec.y, t.vec.y, orig.angle, deshake->avg.angle, t.angle, orig.zoom, deshake->avg.zoom, t.zoom);
-        fwrite(tmp, sizeof(char), strlen(tmp), deshake->fp);
+        fwrite(tmp, 1, strlen(tmp), deshake->fp);
     }
 
     // Turn relative current frame motion into absolute by adding it to the
diff --git a/libavformat/webmdashenc.c b/libavformat/webmdashenc.c
index d05b265330..7847659c63 100644
--- a/libavformat/webmdashenc.c
+++ b/libavformat/webmdashenc.c
@@ -439,7 +439,7 @@ static int write_adaptation_set(AVFormatContext *s, int as_index)
 static int to_integer(char *p, int len)
 {
     int ret;
-    char *q = av_malloc(sizeof(char) * len);
+    char *q = av_malloc(len);
     if (!q)
         return AVERROR(ENOMEM);
     av_strlcpy(q, p, len);