Index: libs/iostreams/test/grep_test.cpp
===================================================================
--- libs/iostreams/test/grep_test.cpp	(revision 49783)
+++ libs/iostreams/test/grep_test.cpp	(working copy)
@@ -253,7 +253,7 @@
                   const std::string& output )
 {
     // Count lines in output
-    ptrdiff_t count = std::count(output.begin(), output.end(), '\n');
+    std::ptrdiff_t count = std::count(output.begin(), output.end(), '\n');
 
     // Test as input filter
     {