diff --git a/libavcodec/eval.c b/libavcodec/eval.c
index 8d79a3341a4f80ac7de37936cc4688b5e5136cf1..d757749e884537d2c2a8c830ca7ea8dc7f7644ae 100644
--- a/libavcodec/eval.c
+++ b/libavcodec/eval.c
@@ -82,11 +82,7 @@ static const int8_t si_prefixes['z' - 'E' + 1]={
     ['Y'-'E']=  24,
 };
 
-/** strtod() function extended with 'k', 'M', 'G', 'ki', 'Mi', 'Gi' and 'B'
- * postfixes.  This allows using f.e. kB, MiB, G and B as a postfix. This
- * function assumes that the unit of numbers is bits not bytes.
- */
-static double av_strtod(const char *numstr, char **tail) {
+double av_strtod(const char *numstr, char **tail) {
     double d;
     char *next;
     d = strtod(numstr, &next);
diff --git a/libavcodec/eval.h b/libavcodec/eval.h
index 82d4315bacf3815579a70dcfcd68ecf98ace0807..6fe70bca5c63ba9831067cfba0c472b1a456504e 100644
--- a/libavcodec/eval.h
+++ b/libavcodec/eval.h
@@ -74,4 +74,10 @@ AVEvalExpr * ff_parse(const char *s, const char * const *const_name,
 double ff_parse_eval(AVEvalExpr * e, const double *const_value, void *opaque);
 void ff_eval_free(AVEvalExpr * e);
 
+/** strtod() function extended with 'k', 'M', 'G', 'ki', 'Mi', 'Gi' and 'B'
+ * postfixes.  This allows using f.e. kB, MiB, G and B as a postfix. This
+ * function assumes that the unit of numbers is bits not bytes.
+ */
+double av_strtod(const char *numstr, char **tail);
+
 #endif /* AVCODEC_EVAL_H */