diff --git a/simgear/nasal/lib.c b/simgear/nasal/lib.c
index 440faaa6..1ed3837b 100644
--- a/simgear/nasal/lib.c
+++ b/simgear/nasal/lib.c
@@ -1,5 +1,6 @@
 #include "nasal.h"
 
+#ifndef _MSC_VER
 // No need to include <string.h> just for this:
 static int strlen(char* s)
 {
@@ -7,6 +8,7 @@ static int strlen(char* s)
     while(*s) s++;
     return s - s0;
 }
+#endif
 
 static naRef size(naContext c, naRef args)
 {
diff --git a/simgear/nasal/mathlib.c b/simgear/nasal/mathlib.c
index 07f8ef81..d967ceed 100644
--- a/simgear/nasal/mathlib.c
+++ b/simgear/nasal/mathlib.c
@@ -1,3 +1,7 @@
+#ifdef _MSC_VER
+#define _USE_MATH_DEFINES
+#endif
+
 #include <math.h>
 #include <string.h>
 
diff --git a/simgear/nasal/parse.c b/simgear/nasal/parse.c
index 22cfed48..a17452c4 100644
--- a/simgear/nasal/parse.c
+++ b/simgear/nasal/parse.c
@@ -107,7 +107,7 @@ void* naParseAlloc(struct Parser* p, int bytes)
         p->leftInChunk = sz;
     }
 
-    result = p->chunks[0] + p->chunkSizes[0] - p->leftInChunk;
+    result = (char *)p->chunks[0] + p->chunkSizes[0] - p->leftInChunk;
     p->leftInChunk -= bytes;
     return (void*)result;
 }