diff --git a/monotonic.py b/monotonic.py
index 1c1b46b..f574ba7 100644
--- a/monotonic.py
+++ b/monotonic.py
@@ -165,5 +165,5 @@ def monotonic():
         if monotonic() - monotonic() > 0:
             raise ValueError('monotonic() is not monotonic!')
 
-    except Exception:
-        raise RuntimeError('no suitable implementation for this system')
+    except Exception as e:
+        raise RuntimeError('no suitable implementation for this system: ' + repr(e))