diff --git a/libbitdht/src/util/bdstring.cc b/libbitdht/src/util/bdstring.cc
index 1eab1bc70..3870b70d6 100644
--- a/libbitdht/src/util/bdstring.cc
+++ b/libbitdht/src/util/bdstring.cc
@@ -25,7 +25,7 @@
 #include <windows.h>
 #else
 #include <stdarg.h>
-#include <malloc.h>
+#include <stdlib.h>
 #endif
 #include <stdio.h>
 
diff --git a/libbitdht/src/util/bdstring.h b/libbitdht/src/util/bdstring.h
index 17cf74d2a..9c4dc94aa 100644
--- a/libbitdht/src/util/bdstring.h
+++ b/libbitdht/src/util/bdstring.h
@@ -22,8 +22,6 @@
  *  Boston, MA  02110-1301, USA.
  ****************************************************************/
 
-#include <string>
-
 #ifdef WIN32
 // for proper handling of %ll
 #define bd_snprintf __mingw_snprintf
@@ -33,7 +31,12 @@
 #define bd_fprintf  fprintf
 #endif
 
-int bd_sprintf(std::string &str, const char *fmt, ...);
-int bd_sprintf_append(std::string &str, const char *fmt, ...);
+#ifdef __cplusplus
+	// These definitions are only available for C++ Modules.
+	#include <string>
+
+	int bd_sprintf(std::string &str, const char *fmt, ...);
+	int bd_sprintf_append(std::string &str, const char *fmt, ...);
+#endif
 
 #endif