diff --git a/extent.cpp b/extent.cpp
index f844f7da..58a31280 100644
--- a/extent.cpp
+++ b/extent.cpp
@@ -99,7 +99,7 @@ template <size_t S, typename T>
 extent<S,T>
 extent<S,T>::contracted (T t) const
 {
-    return *this - vector<S,T> {-t};
+    return *this - vector<S,T> {t};
 }
 
 
diff --git a/test/extent.cpp b/test/extent.cpp
index 1d0f9ff7..c79e47fb 100644
--- a/test/extent.cpp
+++ b/test/extent.cpp
@@ -5,7 +5,12 @@ int
 main (void)
 {
     util::TAP::logger tap;
-    util::extent2f instance;
-    (void) instance;
-    tap.todo ("instancing test");
+
+    {
+        util::extent2u hi { 8, 4 };
+        util::extent2u lo { 6, 2 };
+        tap.expect_eq (lo, hi.contracted (2), "extent scalar contraction by value");
+    }
+
+    return tap.status ();
 }