diff --git a/clutter/cogl/cogl/tesselator/geom.c b/clutter/cogl/cogl/tesselator/geom.c
index 7d3b8d8a6..35b36a394 100644
--- a/clutter/cogl/cogl/tesselator/geom.c
+++ b/clutter/cogl/cogl/tesselator/geom.c
@@ -198,7 +198,7 @@ printf("*********************%d\n",RandomInterpolate);
 
 #endif
 
-#define Swap(a,b)	if (1) { GLUvertex *t = a; a = b; b = t; } else
+#define Swap(a,b)	do { GLUvertex *t = a; a = b; b = t; } while (0)
 
 void __gl_edgeIntersect( GLUvertex *o1, GLUvertex *d1,
 			 GLUvertex *o2, GLUvertex *d2,
diff --git a/clutter/cogl/cogl/tesselator/mesh.c b/clutter/cogl/cogl/tesselator/mesh.c
index 95f87cdc9..36cb3a7be 100644
--- a/clutter/cogl/cogl/tesselator/mesh.c
+++ b/clutter/cogl/cogl/tesselator/mesh.c
@@ -38,8 +38,12 @@
 #include "mesh.h"
 #include "memalloc.h"
 
+#ifndef TRUE
 #define TRUE 1
+#endif
+#ifndef FALSE
 #define FALSE 0
+#endif
 
 static GLUvertex *allocVertex()
 {
diff --git a/clutter/cogl/cogl/tesselator/normal.c b/clutter/cogl/cogl/tesselator/normal.c
index 7ab83167b..9a3bd43d3 100644
--- a/clutter/cogl/cogl/tesselator/normal.c
+++ b/clutter/cogl/cogl/tesselator/normal.c
@@ -39,8 +39,12 @@
 #include <math.h>
 #include <assert.h>
 
+#ifndef TRUE
 #define TRUE 1
+#endif
+#ifndef FALSE
 #define FALSE 0
+#endif
 
 #define Dot(u,v)	(u[0]*v[0] + u[1]*v[1] + u[2]*v[2])
 
diff --git a/clutter/cogl/cogl/tesselator/priorityq-heap.c b/clutter/cogl/cogl/tesselator/priorityq-heap.c
index e3a6c6068..52698b59c 100644
--- a/clutter/cogl/cogl/tesselator/priorityq-heap.c
+++ b/clutter/cogl/cogl/tesselator/priorityq-heap.c
@@ -39,8 +39,12 @@
 
 #define INIT_SIZE	32
 
+#ifndef TRUE
 #define TRUE 1
+#endif
+#ifndef FALSE
 #define FALSE 0
+#endif
 
 #ifdef FOR_TRITE_TEST_PROGRAM
 #define LEQ(x,y)	(*pq->leq)(x,y)
@@ -159,7 +163,7 @@ void pqInit( PriorityQ *pq )
 PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
 {
   long curr;
-  PQhandle free;
+  PQhandle free_handle;
 
   curr = ++ pq->size;
   if( (curr*2) > pq->max ) {
@@ -186,21 +190,21 @@ PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
   }
 
   if( pq->freeList == 0 ) {
-    free = curr;
+    free_handle = curr;
   } else {
-    free = pq->freeList;
-    pq->freeList = pq->handles[free].node;
+    free_handle = pq->freeList;
+    pq->freeList = pq->handles[free_handle].node;
   }
 
-  pq->nodes[curr].handle = free;
-  pq->handles[free].node = curr;
-  pq->handles[free].key = keyNew;
+  pq->nodes[curr].handle = free_handle;
+  pq->handles[free_handle].node = curr;
+  pq->handles[free_handle].key = keyNew;
 
   if( pq->initialized ) {
     FloatUp( pq, curr );
   }
-  assert(free != LONG_MAX);
-  return free;
+  assert(free_handle != LONG_MAX);
+  return free_handle;
 }
 
 /* really __gl_pqHeapExtractMin */
diff --git a/clutter/cogl/cogl/tesselator/priorityq.c b/clutter/cogl/cogl/tesselator/priorityq.c
index 11f0263ac..c6b99cce5 100644
--- a/clutter/cogl/cogl/tesselator/priorityq.c
+++ b/clutter/cogl/cogl/tesselator/priorityq.c
@@ -85,7 +85,7 @@ void pqDeletePriorityQ( PriorityQ *pq )
 
 #define LT(x,y)		(! LEQ(y,x))
 #define GT(x,y)		(! LEQ(x,y))
-#define Swap(a,b)	if(1){PQkey *tmp = *a; *a = *b; *b = tmp;}else
+#define Swap(a,b)	do{PQkey *tmp = *a; *a = *b; *b = tmp;}while(0)
 
 /* really __gl_pqSortInit */
 int pqInit( PriorityQ *pq )
diff --git a/clutter/cogl/cogl/tesselator/render.c b/clutter/cogl/cogl/tesselator/render.c
index 4f376f7f4..bca836f04 100644
--- a/clutter/cogl/cogl/tesselator/render.c
+++ b/clutter/cogl/cogl/tesselator/render.c
@@ -39,8 +39,12 @@
 #include "tess.h"
 #include "render.h"
 
+#ifndef TRUE
 #define TRUE 1
+#endif
+#ifndef FALSE
 #define FALSE 0
+#endif
 
 /* This structure remembers the information we need about a primitive
  * to be able to render it later, once we have determined which
@@ -143,11 +147,11 @@ static void RenderMaximumFaceGroup( GLUtesselator *tess, GLUface *fOrig )
 
 #define AddToTrail(f,t)	((f)->trail = (t), (t) = (f), (f)->marked = TRUE)
 
-#define FreeTrail(t)	if( 1 ) { \
+#define FreeTrail(t)	do { \
 			  while( (t) != NULL ) { \
 			    (t)->marked = FALSE; t = (t)->trail; \
 			  } \
-			} else /* absorb trailing semicolon */
+			} while(0) /* absorb trailing semicolon */
 
 
 
diff --git a/clutter/cogl/cogl/tesselator/sweep.c b/clutter/cogl/cogl/tesselator/sweep.c
index 744be6b47..eca828ff6 100644
--- a/clutter/cogl/cogl/tesselator/sweep.c
+++ b/clutter/cogl/cogl/tesselator/sweep.c
@@ -46,8 +46,12 @@
 #include "memalloc.h"
 #include "sweep.h"
 
+#ifndef TRUE
 #define TRUE 1
+#endif
+#ifndef FALSE
 #define FALSE 0
+#endif
 
 #ifdef FOR_TRITE_TEST_PROGRAM
 extern void DebugEvent( GLUtesselator *tess );
diff --git a/clutter/cogl/cogl/tesselator/tess.c b/clutter/cogl/cogl/tesselator/tess.c
index 029a02c3a..4a0e8dea7 100644
--- a/clutter/cogl/cogl/tesselator/tess.c
+++ b/clutter/cogl/cogl/tesselator/tess.c
@@ -47,8 +47,12 @@
 #define GLU_TESS_DEFAULT_TOLERANCE 0.0
 #define GLU_TESS_MESH		100112	/* void (*)(GLUmesh *mesh)	    */
 
+#ifndef TRUE
 #define TRUE 1
+#endif
+#ifndef FALSE
 #define FALSE 0
+#endif
 
 /*ARGSUSED*/ static void GLAPIENTRY noBegin( GLenum type ) {}
 /*ARGSUSED*/ static void GLAPIENTRY noEdgeFlag( GLboolean boundaryEdge ) {}