diff --git a/lesscpy/plib/call.py b/lesscpy/plib/call.py
index 2555429..f57b24b 100644
--- a/lesscpy/plib/call.py
+++ b/lesscpy/plib/call.py
@@ -49,7 +49,11 @@ class Call(Node):
             
             if hasattr(color, name):
                 try:
-                    return getattr(color, name)(*args)
+                    result = getattr(color, name)(*args)
+                    try:
+                        return result + ' '
+                    except TypeError:
+                        return result
                 except ValueError:
                     pass
             self.parsed = name + ''.join([p for p in parsed])
diff --git a/lesscpy/test/css/issues/issue5.css b/lesscpy/test/css/issues/issue5.css
new file mode 100644
index 0000000..451975c
--- /dev/null
+++ b/lesscpy/test/css/issues/issue5.css
@@ -0,0 +1,3 @@
+.test {
+	border: #3b3b3b solid 1px;
+}
\ No newline at end of file
diff --git a/lesscpy/test/less/issues/issue5.less b/lesscpy/test/less/issues/issue5.less
new file mode 100644
index 0000000..5e87ff0
--- /dev/null
+++ b/lesscpy/test/less/issues/issue5.less
@@ -0,0 +1,3 @@
+.test { 
+	border: darken(#555555, 10%) solid 1px; 
+}
\ No newline at end of file