1 files changed, 7 insertions, 5 deletions
diff --git a/input.c b/input.c
index 718b7cd..62ad271 100644
--- a/input.c
+++ b/input.c
@@ -10,7 +10,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <fenv.h>
+#include <math.h>
 
 char pending_op = 0;
 int making_number = 0;
@@ -27,6 +27,10 @@ double value, saved, stored=0;
 void paste(void);
 void copy(void);
 
+int number_is_ok(double n) {
+	return (fpclassify(n) & (FP_ZERO | FP_NORMAL ));
+}
+
 void bell(void) {
 	if(!quiet)
 		XBell(display, 0);
@@ -81,11 +85,11 @@ show_value()
   char commas[40], *cp, *dp;
   double v = value;
 
-  if(fetestexcept(FE_ALL_EXCEPT)) {
+  if(!number_is_ok(value)) {
     set_string("Err");
     bell();
     showing_err = 1;
-	 value = 0; /* so it doesn't get saved on exit! */
+	 saved = value = 0; /* so it doesn't get saved on exit! */
     return;
   }
 
@@ -236,8 +240,6 @@ key(char c)
   int v = c;
   /* printf("key_number 0x%x\n", v); */
 
-  feclearexcept(FE_ALL_EXCEPT);
-
   if(showing_err) {
     switch(c) {
       /* list the keys that should be still active in error state */