diff --git a/core/math/math-docs.factor b/core/math/math-docs.factor
index 45adc8ab22..c37e788efa 100644
--- a/core/math/math-docs.factor
+++ b/core/math/math-docs.factor
@@ -299,12 +299,12 @@ HELP: unless-zero
 { $examples "This word is equivalent to " { $link if-zero } " with an empty first quotation:"
     { $example
     "USING: sequences math prettyprint ;"
-    "3 [ ] [ sq ] if-zero ."
+    "3 [ ] [ sq . ] if-zero"
     "9"
     }
     { $example
     "USING: sequences math prettyprint ;"
-    "3 [ sq ] unless-zero ."
+    "3 [ sq . ] unless-zero"
     "9"
     }
 } ;
diff --git a/core/math/math.factor b/core/math/math.factor
index 62aadea546..0e556d6109 100644
--- a/core/math/math.factor
+++ b/core/math/math.factor
@@ -152,9 +152,9 @@ GENERIC: neg? ( x -- ? )
 : if-zero ( ..a n quot1: ( ..a -- ..b ) quot2: ( ..a n -- ..b ) -- ..b )
     [ dup zero? ] [ [ drop ] prepose ] [ ] tri* if ; inline
 
-: when-zero ( ..a n quot: ( ..a -- ..b ) -- ..b ) [ ] if-zero ; inline
+: when-zero ( ... n quot: ( ... -- ... x ) -- ... x ) [ ] if-zero ; inline
 
-: unless-zero ( ..a n quot: ( ..a n -- ..b ) -- ..b ) [ ] swap if-zero ; inline
+: unless-zero ( ... n quot: ( ... n -- ... ) -- ... ) [ ] swap if-zero ; inline
 
 UNION: integer fixnum bignum ;