diff --git a/basis/math/complex/complex-tests.factor b/basis/math/complex/complex-tests.factor
index d7fe54b201..537163cb09 100644
--- a/basis/math/complex/complex-tests.factor
+++ b/basis/math/complex/complex-tests.factor
@@ -76,3 +76,6 @@ IN: math.complex.tests
 10 number-base [
     [ "C{ 1/2 2/3 }" ] [ C{ 1/2 2/3 } unparse ] unit-test
 ] with-variable
+
+[ "C{ 1 2 3 }" eval( -- obj ) ]
+[ error>> T{ malformed-complex f V{ 1 2 3 } } = ] must-fail-with
diff --git a/basis/math/complex/complex.factor b/basis/math/complex/complex.factor
index c432089f4d..381f21d693 100644
--- a/basis/math/complex/complex.factor
+++ b/basis/math/complex/complex.factor
@@ -1,7 +1,8 @@
 ! Copyright (C) 2006, 2009 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors kernel kernel.private math math.private
-math.functions arrays math.functions.private sequences parser ;
+math.functions arrays math.functions.private sequences
+sequences.private parser ;
 IN: math.complex.private
 
 M: real real-part ; inline
@@ -30,10 +31,15 @@ M: complex sqrt >polar [ sqrt ] [ 2.0 / ] bi* polar> ; inline
 
 IN: syntax
 
-SYNTAX: C{ \ } [ first2 rect> ] parse-literal ;
+ERROR: malformed-complex obj ;
+
+: parse-complex ( seq -- complex )
+    dup length 2 = [ first2-unsafe rect> ] [ malformed-complex ] if ;
+
+SYNTAX: C{ \ } [ parse-complex ] parse-literal ;
 
 USE: prettyprint.custom
 
 M: complex pprint* pprint-object ;
 M: complex pprint-delims drop \ C{ \ } ;
-M: complex >pprint-sequence >rect 2array ;
\ No newline at end of file
+M: complex >pprint-sequence >rect 2array ;