diff --git a/images-lib/images/private/deep-flomap-render.rkt b/images-lib/images/private/deep-flomap-render.rkt
index f8cd880..6729d54 100644
--- a/images-lib/images/private/deep-flomap-render.rkt
+++ b/images-lib/images/private/deep-flomap-render.rkt
@@ -60,9 +60,9 @@
 
 (: beckmann-distribution (Flonum Flonum -> Flonum))
 (define (beckmann-distribution cos-θ m)
-  (define x (/ (tan (acos cos-θ)) m))
+  (define x (/ (tan (flacos cos-θ)) m))
   (define m*cos^2-θ (* m cos-θ cos-θ))
-  (/ (exp (- (* x x))) (* pi m*cos^2-θ m*cos^2-θ)))
+  (/ (flexp (- (* x x))) (* pi m*cos^2-θ m*cos^2-θ)))
 
 ;; ===================================================================================================
 ;; Pass 1: tracing from a directional light source
diff --git a/images-lib/images/private/flomap-transform.rkt b/images-lib/images/private/flomap-transform.rkt
index 2465026..137f2a4 100644
--- a/images-lib/images/private/flomap-transform.rkt
+++ b/images-lib/images/private/flomap-transform.rkt
@@ -294,13 +294,13 @@
 (define ((orthographic-projection α) d)
   (define f (/ d 2.0 (sin (* 0.5 (real->double-flonum α)))))
   (projection-mapping (λ (ρ) (* (sin ρ) f))
-                      (λ (r) (asin (/ r f)))))
+                      (λ (r) (flasin (/ r f)))))
 
 (: equal-area-projection (Real -> Projection))
 (define ((equal-area-projection α) d)
   (define f (/ d 4.0 (sin (* 0.25 (real->double-flonum α)))))
   (projection-mapping (λ (ρ) (* 2.0 (sin (* 0.5 ρ)) f))
-                      (λ (r) (* 2.0 (asin (/ r 2.0 f))))))
+                      (λ (r) (* 2.0 (flasin (/ r 2.0 f))))))
 
 (: stereographic-projection (Real -> Projection))
 (define ((stereographic-projection α) d)