diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index 3d7b1404a..9808fab07 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -5497,7 +5497,6 @@ inp_modify_exp(char* expr)
 {
     char *s;
     wordlist *wl = NULL, *wlist = NULL;
-    enum { S_value = 0, S_operator, S_unary_minus } state = S_value;
 
     /* scan the expression and remove all '{' and '}' */
     for (s = expr; *s; s++)
@@ -5514,7 +5513,8 @@ inp_modify_exp(char* expr)
 
         if ((c == ',') || (c == '(') || (c == ')') ||
             (c == '*') || (c == '/') || (c == '^') ||
-            (c == '+') || (c == '?') || (c == ':'))
+            (c == '+') || (c == '?') || (c == ':') ||
+            (c == '-'))
         {
             if ((c == '*') && (s[1] == '*')) {
                 wl->wl_word = tprintf("**");
@@ -5523,10 +5523,6 @@ inp_modify_exp(char* expr)
                 wl->wl_word = tprintf("%c", c);
                 s++;
             }
-            if (c == ')')
-                state = S_value;
-            else
-                state = S_operator;
         } else if ((c == '>') || (c == '<') ||
                    (c == '!') || (c == '='))
         {
@@ -5535,29 +5531,16 @@ inp_modify_exp(char* expr)
             if ((*s == '=') || (*s == '<') || (*s == '>'))
                 s++;
             wl->wl_word = copy_substring(beg, s);
-            state = S_operator;
         } else if ((c == '|') || (c == '&')) {
             char *beg = s++;
             if ((*s == '|') || (*s == '&'))
                 s++;
             wl->wl_word = copy_substring(beg, s);
-            state = S_operator;
-        } else if ((c == '-') && (state == S_value)) {
-            wl->wl_word = tprintf("%c", c);
-            s++;
-            state = S_operator;
-        } else if ((c == '-') && (state == S_operator)) {
-            wl->wl_word = copy("");
-            s++;
-            state = S_unary_minus;
         } else if (isalpha(c)) {
 
             char buf[512];
             int i = 0;
 
-            if (state == S_unary_minus)
-                buf[i++] = '-';
-
             if (((c == 'v') || (c == 'i')) && (s[1] == '(')) {
                 while (*s != ')')
                     buf[i++] = *s++;
@@ -5602,15 +5585,11 @@ inp_modify_exp(char* expr)
                     wl->wl_word = tprintf("{%s}", buf);
                 }
             }
-            state = S_value;
         } else if (isdigit(c) || (c == '.')) { /* allow .5 format too */
             int error1;
             /* allow 100p, 5MEG etc. */
             double dvalue = INPevaluate(&s, &error1, 0);
-            if (state == S_unary_minus)
-                dvalue *= -1;
             wl->wl_word = tprintf("%18.10e", dvalue);
-            state = S_value;
             /* skip the `unit', FIXME INPevaluate() should do this */
             while (isalpha(*s))
                 s++;