diff --git a/include/backtrace/BacktraceMap.h b/include/backtrace/BacktraceMap.h
index 13083bd..c717f09 100644
--- a/include/backtrace/BacktraceMap.h
+++ b/include/backtrace/BacktraceMap.h
@@ -18,6 +18,7 @@
 #define _BACKTRACE_BACKTRACE_MAP_H
 
 #include <stdint.h>
+#include <sys/types.h>
 #ifdef USE_MINGW
 // MINGW does not define these constants.
 #define PROT_NONE 0
diff --git a/libbacktrace/UnwindMap.cpp b/libbacktrace/UnwindMap.cpp
index 1615518..4f9831b 100644
--- a/libbacktrace/UnwindMap.cpp
+++ b/libbacktrace/UnwindMap.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <pthread.h>
+#include <stdlib.h>
 #include <sys/types.h>
 #include <unistd.h>