diff --git a/source/blender/blenkernel/intern/unit.c b/source/blender/blenkernel/intern/unit.c
index 1025bee6b8e..c2994e1134c 100644
--- a/source/blender/blenkernel/intern/unit.c
+++ b/source/blender/blenkernel/intern/unit.c
@@ -20,6 +20,7 @@
  *
  * ***** END GPL LICENSE BLOCK *****
  */
+#define _USE_MATH_DEFINES
 
 #include <stdlib.h>
 #include <stdio.h>
diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index 5504daf2994..06b08d677d4 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -21,6 +21,7 @@
  *
  * ***** END GPL LICENSE BLOCK *****
  */
+ #define _USE_MATH_DEFINES
 
 #include <stdlib.h>
 #include <math.h>
diff --git a/source/blender/makesrna/intern/rna_fcurve.c b/source/blender/makesrna/intern/rna_fcurve.c
index ee94d761f03..f77894222d5 100644
--- a/source/blender/makesrna/intern/rna_fcurve.c
+++ b/source/blender/makesrna/intern/rna_fcurve.c
@@ -22,6 +22,8 @@
  * ***** END GPL LICENSE BLOCK *****
  */
 
+ #define _USE_MATH_DEFINES
+ 
 #include <stdlib.h>
 #include <math.h>