diff --git a/snek-poly.c b/snek-poly.c
index cc3e8fb..ac9c224 100644
--- a/snek-poly.c
+++ b/snek-poly.c
@@ -159,3 +159,9 @@ snek_poly_get_soffset(snek_poly_t a)
 {
 	return (snek_soffset_t) snek_poly_get_float(a);
 }
+
+bool
+snek_is_nan(snek_poly_t p)
+{
+	return p.u == SNEK_NAN_U;
+}
diff --git a/snek.h b/snek.h
index e9f6888..3e58367 100644
--- a/snek.h
+++ b/snek.h
@@ -337,11 +337,8 @@ extern snek_offset_t	snek_stackp;
 extern snek_poly_t	snek_a;
 extern snek_code_t	*snek_code;
 
-static inline bool
-snek_is_nan(snek_poly_t p)
-{
-	return p.u == SNEK_NAN_U;
-}
+bool
+snek_is_nan(snek_poly_t p);
 
 static inline bool
 snek_is_null(snek_poly_t p)