diff --git a/src/core/stdc/stdlib.d b/src/core/stdc/stdlib.d
index 6fe432aace..9348c7d107 100644
--- a/src/core/stdc/stdlib.d
+++ b/src/core/stdc/stdlib.d
@@ -157,11 +157,11 @@ else
 // functions using these already have to be @trusted, allowing them to
 // call @system stuff anyway.
 ///
-void*   malloc(size_t size) pure;
+void*   malloc(size_t size);
 ///
-void*   calloc(size_t nmemb, size_t size) pure;
+void*   calloc(size_t nmemb, size_t size);
 ///
-void*   realloc(void* ptr, size_t size) pure;
+void*   realloc(void* ptr, size_t size);
 ///
 void    free(void* ptr);
 
diff --git a/src/core/sys/posix/iconv.d b/src/core/sys/posix/iconv.d
index 816f64632b..792778cd6e 100644
--- a/src/core/sys/posix/iconv.d
+++ b/src/core/sys/posix/iconv.d
@@ -35,7 +35,7 @@ iconv_t iconv_open (in char* tocode, in char* fromcode);
 /// Convert at most *INBYTESLEFT bytes from *INBUF according to the
 /// code conversion algorithm specified by CD and place up to
 /// *OUTBYTESLEFT bytes in buffer at *OUTBUF.
-size_t iconv (iconv_t cd, char** inbuf,
+size_t iconv (iconv_t cd, in char** inbuf,
          size_t* inbytesleft,
          char** outbuf,
          size_t* outbytesleft);
diff --git a/src/core/sys/posix/stdlib.d b/src/core/sys/posix/stdlib.d
index c9450a8412..4afd346d46 100644
--- a/src/core/sys/posix/stdlib.d
+++ b/src/core/sys/posix/stdlib.d
@@ -122,42 +122,42 @@ version( CRuntime_Glibc )
     int setenv(in char*, in char*, int);
     int unsetenv(in char*);
 
-    void* valloc(size_t) pure; // LEGACY non-standard
+    void* valloc(size_t); // LEGACY non-standard
 }
 else version( Darwin )
 {
     int setenv(in char*, in char*, int);
     int unsetenv(in char*);
 
-    void* valloc(size_t) pure; // LEGACY non-standard
+    void* valloc(size_t); // LEGACY non-standard
 }
 else version( FreeBSD )
 {
     int setenv(in char*, in char*, int);
     int unsetenv(in char*);
 
-    void* valloc(size_t) pure; // LEGACY non-standard
+    void* valloc(size_t); // LEGACY non-standard
 }
 else version( OpenBSD )
 {
     int setenv(in char*, in char*, int);
     int unsetenv(in char*);
 
-    void* valloc(size_t) pure; // LEGACY non-standard
+    void* valloc(size_t); // LEGACY non-standard
 }
 else version( CRuntime_Bionic )
 {
     int setenv(in char*, in char*, int);
     int unsetenv(in char*);
 
-    void* valloc(size_t) pure;
+    void* valloc(size_t);
 }
 else version( Solaris )
 {
     int setenv(in char*, in char*, int);
     int unsetenv(in char*);
 
-    void* valloc(size_t) pure; // LEGACY non-standard
+    void* valloc(size_t); // LEGACY non-standard
 }
 
 //
diff --git a/src/rt/monitor_.d b/src/rt/monitor_.d
index f73e32137b..be0672e255 100644
--- a/src/rt/monitor_.d
+++ b/src/rt/monitor_.d
@@ -155,11 +155,6 @@ version (Windows)
     {
         pragma(lib, "snn.lib");
     }
-    else version (CRuntime_Microsoft)
-    {
-        pragma(lib, "libcmt.lib");
-        pragma(lib, "oldnames.lib");
-    }
     import core.sys.windows.windows;
 
     alias Mutex = CRITICAL_SECTION;
diff --git a/win64.mak b/win64.mak
index a9e57e86cd..a025b06f06 100644
--- a/win64.mak
+++ b/win64.mak
@@ -28,6 +28,9 @@ DRUNTIME_BASE=druntime$(MODEL)
 DRUNTIME=lib\$(DRUNTIME_BASE).lib
 GCSTUB=lib\gcstub$(MODEL).obj
 
+# do not preselect a C runtime (extracted from the line above to make the auto tester happy)
+CFLAGS=$(CFLAGS) /Zl
+
 DOCFMT=
 
 target : import copydir copy $(DRUNTIME) $(GCSTUB)