diff --git a/basis/compiler/tree/propagation/known-words/known-words.factor b/basis/compiler/tree/propagation/known-words/known-words.factor
index 63d2df543d..621b8d082b 100644
--- a/basis/compiler/tree/propagation/known-words/known-words.factor
+++ b/basis/compiler/tree/propagation/known-words/known-words.factor
@@ -81,7 +81,10 @@ IN: compiler.tree.propagation.known-words
     class>> dup null-class? [ drop null ] [ math-closure ] if ;
 
 : unary-op-interval ( info quot -- newinterval )
-    [ interval>> ] dip call ; inline
+    [
+        dup class>> real classes-intersect?
+        [ interval>> ] [ drop full-interval ] if
+    ] dip call ; inline
 
 : unary-op ( word interval-quot post-proc-quot -- )
     '[
diff --git a/basis/compiler/tree/propagation/propagation-tests.factor b/basis/compiler/tree/propagation/propagation-tests.factor
index ec5fbd95cd..0c220542ca 100644
--- a/basis/compiler/tree/propagation/propagation-tests.factor
+++ b/basis/compiler/tree/propagation/propagation-tests.factor
@@ -186,6 +186,10 @@ IN: compiler.tree.propagation.tests
 
 [ t ] [ [ { complex } declare absq ] final-info first interval>> [0,inf] = ] unit-test
 
+[ t ] [ [ { float float } declare rect> C{ 0.0 0.0 } + absq ] final-info first interval>> [0,inf] = ] unit-test
+
+[ V{ float } ] [ [ { float float } declare rect> C{ 0.0 0.0 } + absq ] final-classes ] unit-test
+
 [ t ] [ [ [ - absq ] [ + ] 2map-reduce ] final-info first interval>> [0,inf] = ] unit-test
 
 [ t ] [ [ { double-array double-array } declare [ - absq ] [ + ] 2map-reduce ] final-info first interval>> [0,inf] = ] unit-test