diff --git a/src/vector.c b/src/vector.c
index 8c0d2d2..0c6bc83 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -193,14 +193,14 @@ vector_in(PG_FUNCTION_ARGS)
 		CheckElement(x[dim]);
 		dim++;
 
-		while (vector_isspace(*stringEnd))
-          stringEnd++;
-
 		if (stringEnd == pt)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 					 errmsg("invalid input syntax for type vector: \"%s\"", pt)));
 
+		while (vector_isspace(*stringEnd))
+			stringEnd++;
+
 		if (*stringEnd != '\0' && *stringEnd != ']')
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),