diff --git a/SConstruct b/SConstruct
index 57d853926..6e9aa63fa 100644
--- a/SConstruct
+++ b/SConstruct
@@ -608,7 +608,7 @@ class DXXArchive(DXXCommon):
 '2d/circle.cpp',
 '2d/disc.cpp',
 '2d/gpixel.cpp',
-'2d/line.c',
+'2d/line.cpp',
 '2d/pixel.c',
 '2d/rect.c',
 '2d/rle.c',
diff --git a/common/2d/line.c b/common/2d/line.cpp
similarity index 100%
rename from common/2d/line.c
rename to common/2d/line.cpp
diff --git a/common/include/maths.h b/common/include/maths.h
index 0518b5e31..f6b71b273 100644
--- a/common/include/maths.h
+++ b/common/include/maths.h
@@ -10,6 +10,10 @@
 
 #define D_RAND_MAX 32767
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void d_srand (unsigned int seed);
 int d_rand ();			// Random number function which returns in the range 0-0x7FFF
 
@@ -114,4 +118,8 @@ extern const short sincos_table[321];
 extern const ushort asin_table[258];
 extern const ushort acos_table[258];
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif