diff --git a/core/math/floats/floats-tests.factor b/core/math/floats/floats-tests.factor
index 84f993c5ac..3893e0cc9f 100644
--- a/core/math/floats/floats-tests.factor
+++ b/core/math/floats/floats-tests.factor
@@ -62,6 +62,21 @@ unit-test
 
 [ 5 ] [ 10.5 1.9 /i ] unit-test
 
+[ t ] [ 0   0   /f                 fp-nan? ] unit-test
+[ t ] [ 0.0 0.0 /f                 fp-nan? ] unit-test
+[ t ] [ 0.0 0.0 /                  fp-nan? ] unit-test
+[ t ] [ 0   0   [ >bignum ] bi@ /f fp-nan? ] unit-test
+
+[ 1/0. ] [ 1 0 /f ] unit-test
+[ 1/0. ] [ 1.0 0.0 /f ] unit-test
+[ 1/0. ] [ 1.0 0.0 / ] unit-test
+[ 1/0. ] [ 1 0 [ >bignum ] bi@ /f ] unit-test
+
+[ -1/0. ] [ -1 0 /f ] unit-test
+[ -1/0. ] [ -1.0 0.0 /f ] unit-test
+[ -1/0. ] [ -1.0 0.0 / ] unit-test
+[ -1/0. ] [ -1 0 [ >bignum ] bi@ /f ] unit-test
+
 [ t ] [ 0/0. 0/0. unordered? ] unit-test
 [ t ] [ 1.0 0/0. unordered? ] unit-test
 [ t ] [ 0/0. 1.0 unordered? ] unit-test
diff --git a/core/math/integers/integers.factor b/core/math/integers/integers.factor
index 4dd948021a..a3be60ed35 100644
--- a/core/math/integers/integers.factor
+++ b/core/math/integers/integers.factor
@@ -142,12 +142,8 @@ M: bignum (log2) bignum-log2 ; inline
 
 ! Main word
 : /f-abs ( m n -- f )
-    over zero? [
-        2drop 0.0
-    ] [
-        [
-            drop 1/0.
-        ] [
+    over zero? [ nip zero? 0/0. 0.0 ? ] [
+        [ drop 1/0. ] [
             pre-scale
             /f-loop
             [ over odd? [ zero? [ 1 + ] unless ] [ drop ] if ] dip