diff --git a/v3.h b/v3.h
index 94ab428..8e5b485 100644
--- a/v3.h
+++ b/v3.h
@@ -12,6 +12,19 @@
 #define 	M_PI   3.1415926535897932384
 #endif
 
+static inline float
+sign(
+	const float x
+)
+{
+	if (x < 0)
+		return -1;
+	if (x > 0)
+		return +1;
+	return 0;
+}
+
+
 
 typedef struct
 {
diff --git a/wireframe.c b/wireframe.c
index 8ac648f..13559ea 100644
--- a/wireframe.c
+++ b/wireframe.c
@@ -140,19 +140,6 @@ coplanar_check(
 }
 
 
-static inline float
-sign(
-	const float x
-)
-{
-	if (x < 0)
-		return -1;
-	if (x > 0)
-		return +1;
-	return 0;
-}
-
-
 
 /**
  * Add a vector to the list of edges if it is not already present