diff --git a/src/clapack/F2CLIBS/libf2c/f2ch.add b/src/clapack/F2CLIBS/libf2c/f2ch.add
index a22b0d3d..9425ca37 100644
--- a/src/clapack/F2CLIBS/libf2c/f2ch.add
+++ b/src/clapack/F2CLIBS/libf2c/f2ch.add
@@ -126,7 +126,7 @@ extern double r_tan(float *);
 extern double r_tanh(float *);
 extern integer s_cat(char *, char **, integer *, integer *, ftnlen);
 extern integer s_cmp(char *, char *, ftnlen, ftnlen);
-extern void s_copy(char *, char *, ftnlen, ftnlen);
+extern integer s_copy(char *, char *, ftnlen, ftnlen);
 extern int s_paus(char *, ftnlen);
 extern integer s_rdfe(cilist *);
 extern integer s_rdue(cilist *);