diff --git a/mongoose.h b/mongoose.h
index f768c8d9..de7eeab3 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -228,7 +228,7 @@
 #include <windows.h>
 #include <process.h>
 
-#if _MSC_VER < 1700
+#if defined(_MSC_VER) && (_MSC_VER < 1700)
 typedef int bool;
 #else
 #include <stdbool.h>
diff --git a/src/common/platforms/platform_windows.h b/src/common/platforms/platform_windows.h
index 3b300bd6..f2eb95ae 100644
--- a/src/common/platforms/platform_windows.h
+++ b/src/common/platforms/platform_windows.h
@@ -50,7 +50,7 @@
 #include <windows.h>
 #include <process.h>
 
-#if _MSC_VER < 1700
+#if defined(_MSC_VER) && (_MSC_VER < 1700)
 typedef int bool;
 #else
 #include <stdbool.h>