diff --git a/lib/Analysis/PrintfFormatString.cpp b/lib/Analysis/PrintfFormatString.cpp
index 357080f..05b5d9c 100644
--- a/lib/Analysis/PrintfFormatString.cpp
+++ b/lib/Analysis/PrintfFormatString.cpp
@@ -309,6 +309,9 @@
         // version of ptrdiff_t?
         return ArgTypeResult();
     }
+  
+  if (CS.isDoubleArg())
+    return Ctx.DoubleTy;
 
   // FIXME: Handle other cases.
   return ArgTypeResult();
diff --git a/test/Sema/format-strings.c b/test/Sema/format-strings.c
index f1ab868..21d7770 100644
--- a/test/Sema/format-strings.c
+++ b/test/Sema/format-strings.c
@@ -160,6 +160,7 @@
   printf("%"); // expected-warning{{incomplete format specifier}}
   printf("%.d", x); // no-warning
   printf("%.", x);  // expected-warning{{incomplete format specifier}}
+  printf("%f", 4); // expected-warning{{conversion specifies type 'double' but the argument has type 'int'}}
 } 
 
 typedef struct __aslclient *aslclient;