diff --git a/basis/persistent/vectors/vectors-docs.factor b/basis/persistent/vectors/vectors-docs.factor
index 4816877a35..aa817edf52 100644
--- a/basis/persistent/vectors/vectors-docs.factor
+++ b/basis/persistent/vectors/vectors-docs.factor
@@ -2,7 +2,7 @@ USING: help.markup help.syntax kernel math sequences ;
 IN: persistent.vectors
 
 HELP: PV{
-{ $syntax "elements... }" }
+{ $syntax "PV{ elements... }" }
 { $description "Parses a literal " { $link persistent-vector } "." } ;
 
 HELP: >persistent-vector
diff --git a/core/lexer/lexer-docs.factor b/core/lexer/lexer-docs.factor
index 31f5a3f72e..fcfd0806d4 100644
--- a/core/lexer/lexer-docs.factor
+++ b/core/lexer/lexer-docs.factor
@@ -29,7 +29,7 @@ HELP: <lexer-error>
 
 HELP: skip
 { $values { "i" "a starting index" } { "seq" sequence } { "?" "a boolean" } { "n" integer } }
-{ $description "Skips to the first space character (if " { $snippet "boolean" } " is " { $link f } ") or the first non-space character (otherwise)." } ;
+{ $description "Skips to the first space character (if " { $snippet "boolean" } " is " { $link f } ") or the first non-space character (otherwise). Tabulations used as separators instead of spaces will be flagged as an error." } ;
 
 HELP: change-lexer-column
 { $values { "lexer" lexer } { "quot" { $quotation "( col line -- newcol )" } } }
diff --git a/core/lexer/lexer.factor b/core/lexer/lexer.factor
index 60157033d7..99e6f05c6c 100644
--- a/core/lexer/lexer.factor
+++ b/core/lexer/lexer.factor
@@ -22,9 +22,17 @@ TUPLE: lexer text line line-text line-length column ;
 : <lexer> ( text -- lexer )
     lexer new-lexer ;
 
+ERROR: unexpected want got ;
+
+PREDICATE: unexpected-tab < unexpected
+    got>> CHAR: \t = ;
+
+: forbid-tab ( c -- c )
+    [ CHAR: \t eq? [ "[space]" "[tab]" unexpected ] when ] keep ;
+
 : skip ( i seq ? -- n )
     over length
-    [ [ swap CHAR: \s eq? xor ] curry find-from drop ] dip or ;
+    [ [ swap forbid-tab CHAR: \s eq? xor ] curry find-from drop ] dip or ;
 
 : change-lexer-column ( lexer quot -- )
     [ [ column>> ] [ line-text>> ] bi ] prepose keep
@@ -65,8 +73,6 @@ M: lexer skip-word ( lexer -- )
 
 : scan ( -- str/f ) lexer get parse-token ;
 
-ERROR: unexpected want got ;
-
 PREDICATE: unexpected-eof < unexpected
     got>> not ;