diff --git a/basis/compiler/tests/optimizer.factor b/basis/compiler/tests/optimizer.factor
index d051031d4a..f19a950711 100644
--- a/basis/compiler/tests/optimizer.factor
+++ b/basis/compiler/tests/optimizer.factor
@@ -4,7 +4,7 @@ sbufs strings tools.test vectors words sequences.private
 quotations classes classes.algebra classes.tuple.private
 continuations growable namespaces hints alien.accessors
 compiler.tree.builder compiler.tree.optimizer sequences.deep
-compiler ;
+compiler definitions ;
 IN: compiler.tests.optimizer
 
 GENERIC: xyz ( obj -- obj )
@@ -384,3 +384,9 @@ DEFER: loop-bbb
     1 >bignum 2 >bignum
     [ { bignum integer } declare [ shift ] keep 1+ ] compile-call
 ] unit-test
+
+: broken-declaration ( -- ) \ + declare ;
+
+[ f ] [ \ broken-declaration optimized? ] unit-test
+
+[ ] [ [ \ broken-declaration forget ] with-compilation-unit ] unit-test
\ No newline at end of file
diff --git a/basis/hints/hints.factor b/basis/hints/hints.factor
index d83275c750..db04033275 100644
--- a/basis/hints/hints.factor
+++ b/basis/hints/hints.factor
@@ -71,7 +71,7 @@ t specialize-method? set-global
 SYNTAX: HINTS:
     scan-object
     [ changed-definition ]
-    [ parse-definition "specializer" set-word-prop ] bi ;
+    [ parse-definition { } like "specializer" set-word-prop ] bi ;
 
 ! Default specializers
 { first first2 first3 first4 }
diff --git a/basis/stack-checker/errors/errors.factor b/basis/stack-checker/errors/errors.factor
index e036d4d81b..b1071df708 100644
--- a/basis/stack-checker/errors/errors.factor
+++ b/basis/stack-checker/errors/errors.factor
@@ -33,4 +33,6 @@ ERROR: unknown-primitive-error < inference-error ;
 
 ERROR: transform-expansion-error < inference-error word error ;
 
+ERROR: bad-declaration-error < inference-error declaration ;
+
 M: object (literal) "literal value" literal-expected ;
\ No newline at end of file
diff --git a/basis/stack-checker/known-words/known-words.factor b/basis/stack-checker/known-words/known-words.factor
index 72eead1826..d7acf77162 100644
--- a/basis/stack-checker/known-words/known-words.factor
+++ b/basis/stack-checker/known-words/known-words.factor
@@ -10,7 +10,7 @@ sequences sequences.private slots.private strings
 strings.private system threads.private classes.tuple
 classes.tuple.private vectors vectors.private words definitions
 assocs summary compiler.units system.private
-combinators locals locals.backend locals.types
+combinators combinators.short-circuit locals locals.backend locals.types
 quotations.private combinators.private stack-checker.values
 generic.single generic.single.private
 alien.libraries
@@ -58,8 +58,12 @@ IN: stack-checker.known-words
 : infer-shuffle-word ( word -- )
     "shuffle" word-prop infer-shuffle ;
 
+: check-declaration ( declaration -- declaration )
+    dup { [ array? ] [ [ class? ] all? ] } 1&&
+    [ bad-declaration-error ] unless ;
+
 : infer-declare ( -- )
-    pop-literal nip
+    pop-literal nip check-declaration
     [ length ensure-d ] keep zip
     #declare, ;