diff --git a/extra/modern/modern-tests.factor b/extra/modern/modern-tests.factor
index 5c85b47aa6..68e43dc65a 100644
--- a/extra/modern/modern-tests.factor
+++ b/extra/modern/modern-tests.factor
@@ -11,6 +11,16 @@ IN: modern.tests
 { t } [ "FOO::" upper-colon? ] unit-test
 { t } [ "FOO:::" upper-colon? ] unit-test
 
+! 'FOO:
+{ f } [ "'" upper-colon? ] unit-test
+{ t } [ "':" upper-colon? ] unit-test
+{ t } [ "'::" upper-colon? ] unit-test
+{ t } [ "':::" upper-colon? ] unit-test
+{ t } [ "'FOO:" upper-colon? ] unit-test
+{ t } [ "'FOO::" upper-colon? ] unit-test
+{ t } [ "'FOO:::" upper-colon? ] unit-test
+
+! \FOO: is not an upper-colon form, it is deactivated by the \
 { f } [ "\\" upper-colon? ] unit-test
 { f } [ "\\:" upper-colon? ] unit-test
 { f } [ "\\::" upper-colon? ] unit-test
diff --git a/extra/modern/modern.factor b/extra/modern/modern.factor
index f2c905ab1d..a4eb778ac4 100644
--- a/extra/modern/modern.factor
+++ b/extra/modern/modern.factor
@@ -158,12 +158,14 @@ ERROR: unexpected-terminator n string slice ;
 
 : (strict-upper?) ( string -- ? )
     {
+        ! All chars must...
         [
             [
-                { [ char: A char: Z between? ] [ ":-\\#" member? ] } 1||
+                { [ char: A char: Z between? ] [ "':-\\#" member? ] } 1||
             ] all?
         ]
-        [ [ char: A char: Z between? ] any? ] ! XXX: what?
+        ! At least one char must...
+        [ [ { [ char: A char: Z between? ] [ char: ' = ] } 1|| ] any? ]
     } 1&& ;
 
 : strict-upper? ( string -- ? )