diff --git a/man3/ecvt.3 b/man3/ecvt.3
index ec4a4b6fc..8d53b1287 100644
--- a/man3/ecvt.3
+++ b/man3/ecvt.3
@@ -36,8 +36,10 @@ ecvt, fcvt \- convert a floating-point number to a string
 .nf
 .B #include <stdlib.h>
 .PP
-.BI "char *ecvt(double " number ", int " ndigits ", int *" decpt ", int *" sign );
-.BI "char *fcvt(double " number ", int " ndigits ", int *" decpt ", int *" sign );
+.BI "char *ecvt(double " number ", int " ndigits ", int *restrict " decpt ,
+.BI "           int *restrict " sign );
+.BI "char *fcvt(double " number ", int " ndigits ", int *restrict " decpt ,
+.BI "           int *restrict " sign );
 .fi
 .PP
 .RS -4