diff --git a/c/cmake_lib/libmean/mean.c b/c/cmake_lib/libmean/mean.c
index e4d580e..8755b77 100644
--- a/c/cmake_lib/libmean/mean.c
+++ b/c/cmake_lib/libmean/mean.c
@@ -1,5 +1,7 @@
-//#include <stdio.h>
+#if defined (__BORLANDC__)
 #define __DLL_MEAN__
+#endif
+
 #include "mean.h"
 
 double DLL_SPEC mean(double a, double b) {
diff --git a/c/cmake_lib/libmean/mean.h b/c/cmake_lib/libmean/mean.h
index 5df4d3d..52dc490 100644
--- a/c/cmake_lib/libmean/mean.h
+++ b/c/cmake_lib/libmean/mean.h
@@ -1,7 +1,11 @@
-#if defined(__DLL_MEAN__)
-	#define DLL_SPEC __declspec(dllexport)
+#if defined (__BORLANDC__)
+  #if defined(__DLL_MEAN__)
+    #define DLL_SPEC __declspec(dllexport)
+  #else
+    #define DLL_SPEC __declspec(dllimport)
+  #endif
 #else
-	#define DLL_SPEC __declspec(dllimport)
+  #define DLL_SPEC
 #endif