diff --git a/basis/stack-checker/errors/errors.factor b/basis/stack-checker/errors/errors.factor
index 9fb2b59f6c..31ae0a6789 100644
--- a/basis/stack-checker/errors/errors.factor
+++ b/basis/stack-checker/errors/errors.factor
@@ -108,3 +108,9 @@ M: inconsistent-recursive-call-error error.
     "The recursive word " write
     word>> pprint
     " calls itself with a different set of quotation parameters than were input" print ;
+
+TUPLE: unknown-primitive-error ;
+
+M: unknown-primitive-error error.
+    drop
+    "Cannot determine stack effect statically" print ;
diff --git a/basis/stack-checker/known-words/known-words.factor b/basis/stack-checker/known-words/known-words.factor
index 4aea0f2d28..f1034f2ca6 100644
--- a/basis/stack-checker/known-words/known-words.factor
+++ b/basis/stack-checker/known-words/known-words.factor
@@ -162,7 +162,7 @@ M: object infer-call*
         { \ load-locals [ infer-load-locals ] }
         { \ get-local [ infer-get-local ] }
         { \ drop-locals [ infer-drop-locals ] }
-        { \ do-primitive [ \ do-primitive cannot-infer-effect ] }
+        { \ do-primitive [ unknown-primitive-error inference-error ] }
         { \ alien-invoke [ infer-alien-invoke ] }
         { \ alien-indirect [ infer-alien-indirect ] }
         { \ alien-callback [ infer-alien-callback ] }
diff --git a/basis/stack-checker/stack-checker-tests.factor b/basis/stack-checker/stack-checker-tests.factor
index 9bf8ed62f0..defcde53f0 100644
--- a/basis/stack-checker/stack-checker-tests.factor
+++ b/basis/stack-checker/stack-checker-tests.factor
@@ -580,3 +580,5 @@ DEFER: eee'
     dup "A" throw [ bogus-error ] [ drop ] if ; inline recursive
 
 [ bogus-error ] must-infer
+
+[ [ clear ] infer. ] [ inference-error? ] must-fail-with