diff --git a/src/frontend/numparam/general.h b/src/frontend/numparam/general.h
index 6c02a5a35..2aa8aa978 100644
--- a/src/frontend/numparam/general.h
+++ b/src/frontend/numparam/general.h
@@ -31,7 +31,6 @@ bool stne(const char *s, const char *t);
 void stri(long n, SPICE_DSTRINGPTR s);
 
 char upcase(char c);
-char lowcase(char c);
 bool alfa(char c);
 bool num(char c);
 bool alfanum(char c);
diff --git a/src/frontend/numparam/mystring.c b/src/frontend/numparam/mystring.c
index cfd9ffb16..bb46dd1e8 100644
--- a/src/frontend/numparam/mystring.c
+++ b/src/frontend/numparam/mystring.c
@@ -214,7 +214,7 @@ scopy_lower(SPICE_DSTRINGPTR dstr_p, const char *str) /* returns success flag */
     spice_dstring_reinit(dstr_p);
     low[1] = '\0';
     for (ptr = str; ptr && *ptr; ptr++) {
-        low[0] = lowcase(*ptr);
+        low[0] = tolower_c(*ptr);
         spice_dstring_append(dstr_p, low, 1);
     }
 }
@@ -390,16 +390,6 @@ stne(const char *s, const char *t)
 }
 
 
-char
-lowcase(char c)
-{
-    if ((c >= 'A') && (c <= 'Z'))
-        return (char) (c - 'A' + 'a');
-    else
-        return c;
-}
-
-
 bool
 alfa(char c)
 {