diff --git a/src/humidity/core.clj b/src/humidity/core.clj
index 6267107..5bc3387 100644
--- a/src/humidity/core.clj
+++ b/src/humidity/core.clj
@@ -2,41 +2,47 @@
   (:require [humidity.absolute :refer [abs-humidity]]
             [humidity.constants :refer [celsius-offset Pa]]
             [humidity.relative :refer [rel-humidity]]
-            [humidity.saturation-vp :as saturation-vp]
+            [humidity.saturation-vp :refer [saturation-vp]]
             [humidity.utils :refer [?assoc]]
-            [humidity.wet-bulb :refer [wet-bulb-temperature]]))
+            [humidity.wet-bulb :as wb]))
 
 (defn resolve-humidity
   "Resolve humidity equations given the data in this packet."
-  [& {:keys [temperature temperature-celsius temperature-kelvin relative-humidity
-             pressure-pascals pressure-millibars saturation-vapour-pressure] :as packet}]
+  [& {:keys [absolute-humidity pressure-pascals pressure-millibars
+             relative-humidity saturation-vapour-pressure temperature
+             temperature-celsius temperature-kelvin wet-bulb-temperature] :as packet}]
   (println packet)
-  (if temperature (resolve-humidity (assoc (dissoc packet :temperature) :temperature-celsius temperature))
+  (if temperature (resolve-humidity
+                   (assoc (dissoc packet :temperature)
+                          :temperature-celsius temperature))
       (?assoc packet
+              :absolute-humidity (when-not absolute-humidity
+                                   (abs-humidity packet))
+              :pressure-pascals (when-not pressure-pascals
+                                  (if pressure-millibars
+                                    (* pressure-millibars 100) Pa))
+              :pressure-millibars (when-not pressure-millibars
+                                    (if pressure-pascals
+                                      (/ pressure-pascals 100) (/ Pa 100)))
+              :relative-humidity (when-not relative-humidity
+                                   (rel-humidity packet))
+              :saturation-vapour-pressure (when-not saturation-vapour-pressure
+                                            (saturation-vp packet))
               :temperature-celsius (when
-                                    (and temperature-kelvin (not temperature-celsius))
+                                    (and temperature-kelvin
+                                         (not temperature-celsius))
                                      (- temperature-kelvin celsius-offset))
               :temperature-kelvin (when
-                                   (and temperature-celsius (not temperature-kelvin))
+                                   (and temperature-celsius
+                                        (not temperature-kelvin))
                                     (+ temperature-celsius celsius-offset))
-              :wet-bulb-temperature (when
-                                     (and temperature-celsius relative-humidity)
-                                      (wet-bulb-temperature temperature-celsius relative-humidity))
-              :absolute-humidity (abs-humidity :relative-humidity relative-humidity
-                :saturation-vapour-pressure saturation-vapour-pressure
-                :temperature-kelvin temperature-kelvin)
-              :pressure-pascals (when-not pressure-pascals
-                                      (if pressure-millibars (* pressure-millibars 100) Pa))
-              :pressure-millibars (when-not pressure-millibars
-                                    (if pressure-pascals (/ pressure-pascals 100) (/ Pa 100)))
-              :relative-humidity (when-not relative-humidity (rel-humidity packet))
-              :saturation-vapour-pressure (saturation-vp/saturation-vp packet))))
-
+              :wet-bulb-temperature (when-not wet-bulb-temperature
+                (wb/wet-bulb-temperature packet)))))
 
 (defn resolution
   "Repeatedly run `resolve-humidity`, q.v., until we can infer no further
    information."
-  [packet]
+  [& {:keys [] :as packet}]
   (loop [p packet]
     (let [p' (resolve-humidity p)]
       (if (= (keys p) (keys p')) p
diff --git a/src/humidity/wet_bulb.clj b/src/humidity/wet_bulb.clj
index ffed146..04b4488 100644
--- a/src/humidity/wet_bulb.clj
+++ b/src/humidity/wet_bulb.clj
@@ -17,11 +17,13 @@
 (defn wet-bulb-temperature
   "Returns wet bulb temperature (in ° C) given this `temperature` in
    ° C and `relative-humidity` percentage (0...100)"
-  [temperature relative-humidity]
-  (let [T temperature
+  [&{:keys [temperature relative-humidity]}]
+  (when
+    (and temperature relative-humidity)
+    (let [T temperature
         RHP relative-humidity]
     (+ (* T (atan (* (C 1) (expt (+ RHP (C 2)) 1/2))))
        (atan (+ T RHP))
        (- 0 (atan (- RHP (C 3))))
        (* (C 4) (expt RHP 3/2) (atan (* (C 5) RHP)))
-       (- 0 (C 6)))))
+       (- 0 (C 6))))))
diff --git a/test/humidity/wet_bulb_test.clj b/test/humidity/wet_bulb_test.clj
index 6dc802b..6678cf9 100644
--- a/test/humidity/wet_bulb_test.clj
+++ b/test/humidity/wet_bulb_test.clj
@@ -8,7 +8,7 @@
     (let [expected 13.7
           temperature 20
           rel-humidity 50
-          actual (wet-bulb-temperature temperature rel-humidity)]
+          actual (wet-bulb-temperature :temperature temperature :relative-humidity rel-humidity)]
       (println (format "Expected: %s; actual: %s" expected actual))
       (is (< (abs (- expected actual)) 0.001))))
 
@@ -17,7 +17,7 @@
           max-expected 33
           temperature 37
           rel-humidity 70
-          actual (wet-bulb-temperature temperature rel-humidity)]
+          actual (wet-bulb-temperature :temperature temperature :relative-humidity rel-humidity)]
       (println (format "Expected: %s...%s; actual: %s" min-expected max-expected actual))
       (is (< min-expected actual max-expected)))
 
@@ -25,7 +25,7 @@
           max-expected 36
           temperature 39.7
           rel-humidity 70
-          actual (wet-bulb-temperature temperature rel-humidity)]
+          actual (wet-bulb-temperature :temperature temperature :relative-humidity rel-humidity)]
       (println (format "Expected: %s...%s; actual: %s" min-expected max-expected actual))
       (is (< min-expected actual max-expected)))
 
@@ -34,7 +34,7 @@
           max-expected 34
           temperature 40
           rel-humidity 60
-          actual (wet-bulb-temperature temperature rel-humidity)]
+          actual (wet-bulb-temperature :temperature temperature :relative-humidity rel-humidity)]
       (println (format "Expected: %s...%s; actual: %s" min-expected max-expected actual))
       (is (< min-expected actual max-expected)))
 
@@ -42,6 +42,6 @@
           max-expected 35
           temperature 51
           rel-humidity 30
-          actual (wet-bulb-temperature temperature rel-humidity)]
+          actual (wet-bulb-temperature :temperature temperature :relative-humidity rel-humidity)]
       (println (format "Expected: %s...%s; actual: %s" min-expected max-expected actual))
-      (is (< min-expected actual max-expected)))))
\ No newline at end of file
+      (is (< min-expected actual max-expected)))))