diff --git a/src/c/number.d b/src/c/number.d
index 51659c54e..06d1dee4e 100644
--- a/src/c/number.d
+++ b/src/c/number.d
@@ -916,3 +916,23 @@ _ecl_float_to_integer(float d)
     return _ecl_big_register_copy(z);
   }
 }
+
+#ifdef ECL_IEEE_FP
+cl_object
+si_nan() {
+#ifdef ECL_LONG_FLOAT
+  ecl_make_long_float(NAN);
+#else
+  ecl_make_double_float(NAN);
+#endif
+}
+
+cl_object
+si_infinity() {
+#ifdef ECL_LONG_FLOAT
+  ecl_make_long_float(INFINITY);
+#else
+  ecl_make_double_float(INFINITY);
+#endif
+}
+#endif /* ECL_IEEE_FP */
diff --git a/src/c/symbols_list.h b/src/c/symbols_list.h
index 317b08677..81e099a16 100755
--- a/src/c/symbols_list.h
+++ b/src/c/symbols_list.h
@@ -1901,6 +1901,9 @@ cl_symbols[] = {
 {EXT_ "*BYTECODES-COMPILER*", EXT_SPECIAL, NULL, -1, ECL_NIL},
 
 #ifdef ECL_IEEE_FP
+{SYS_ "NAN", EXT_ORDINARY, si_nan, 0, OBJNULL},
+{SYS_ "INFINITY", EXT_ORDINARY, si_infinity, 0, OBJNULL},
+
 {EXT_ "SHORT-FLOAT-POSITIVE-INFINITY", EXT_CONSTANT, NULL, -1, OBJNULL},
 {EXT_ "SINGLE-FLOAT-POSITIVE-INFINITY", EXT_CONSTANT, NULL, -1, OBJNULL},
 {EXT_ "DOUBLE-FLOAT-POSITIVE-INFINITY", EXT_CONSTANT, NULL, -1, OBJNULL},
diff --git a/src/c/symbols_list2.h b/src/c/symbols_list2.h
index 310a3dced..8c90e3b1c 100644
--- a/src/c/symbols_list2.h
+++ b/src/c/symbols_list2.h
@@ -1901,6 +1901,9 @@ cl_symbols[] = {
 {EXT_ "*BYTECODES-COMPILER*",NULL},
 
 #ifdef ECL_IEEE_FP
+{SYS_ "NAN","si_nan"},
+{SYS_ "INFINITY","si_infinity"},
+
 {EXT_ "SHORT-FLOAT-POSITIVE-INFINITY",NULL},
 {EXT_ "SINGLE-FLOAT-POSITIVE-INFINITY",NULL},
 {EXT_ "DOUBLE-FLOAT-POSITIVE-INFINITY",NULL},
diff --git a/src/doc/new-doc/standards/index.txi b/src/doc/new-doc/standards/index.txi
index 6860d3c1c..e33e6b6a0 100644
--- a/src/doc/new-doc/standards/index.txi
+++ b/src/doc/new-doc/standards/index.txi
@@ -61,7 +61,9 @@
 @node Numbers
 @section Numbers
 @c build option --with-ieee-fp={yes|no}
-
+@c si::trap-fpe
+@c si::nan
+@c si::infinity
 @c ext:{short,single,double,long}-float-{positive,negative}-infinity
 @c ext:float-nan-p
 @c ext:float-infinity-p
diff --git a/src/h/external.h b/src/h/external.h
index 64aea9cdd..285b06d36 100755
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -1117,6 +1117,10 @@ extern ECL_API double ecl_to_double(cl_object x);
 extern ECL_API long double ecl_to_long_double(cl_object x);
 extern ECL_API cl_object ecl_make_long_float(long double f);
 #endif
+#ifdef ECL_IEEE_FP
+extern cl_object si_nan();
+extern cl_object si_infinity();
+#endif /* ECL_IEEE_FP */
 
 /* num_co.c */
 
diff --git a/src/lsp/numlib.lsp b/src/lsp/numlib.lsp
index 8cb4e86ad..b96e20cf4 100644
--- a/src/lsp/numlib.lsp
+++ b/src/lsp/numlib.lsp
@@ -74,22 +74,15 @@
     ))
 
 #+ieee-floating-point
-(locally
- (declare (notinline -))
- (let* ((bits (si::trap-fpe 'last nil)))
-   (let ((a (/ (coerce 1 'short-float) (coerce 0.0 'short-float))))
-     (defconstant short-float-positive-infinity a)
-     (defconstant short-float-negative-infinity (- a)))
-   (let ((a (/ (coerce 1 'single-float) (coerce 0.0 'single-float))))
-     (defconstant single-float-positive-infinity a)
-     (defconstant single-float-negative-infinity (- a)))
-   (let ((a (/ (coerce 1 'double-float) (coerce 0.0 'double-float))))
-     (defconstant double-float-positive-infinity a)
-     (defconstant double-float-negative-infinity (- a)))
-   (let ((a (/ (coerce 1 'long-float) (coerce 0.0 'long-float))))
-     (defconstant long-float-positive-infinity a)
-     (defconstant long-float-negative-infinity (- a)))
-   (si::trap-fpe bits t)))
+(let ((inf (si::infinity)))
+  (defconstant short-float-positive-infinity  (coerce inf     'short-float))
+  (defconstant short-float-negative-infinity  (coerce (- inf) 'short-float))
+  (defconstant single-float-positive-infinity (coerce inf     'single-float))
+  (defconstant single-float-negative-infinity (coerce (- inf) 'single-float))
+  (defconstant double-float-positive-infinity (coerce inf     'double-float))
+  (defconstant double-float-negative-infinity (coerce (- inf) 'double-float))
+  (defconstant long-float-positive-infinity   (coerce inf     'long-float))
+  (defconstant long-float-negative-infinity   (coerce (- inf) 'long-float)))
 
 (defconstant imag-one #C(0.0 1.0))