diff --git a/Source/HarmonyPatches/HealthAIUtility_FindBestMedicine.cs b/Source/HarmonyPatches/HealthAIUtility_FindBestMedicine.cs
index 3163aaa..00f2bd7 100644
--- a/Source/HarmonyPatches/HealthAIUtility_FindBestMedicine.cs
+++ b/Source/HarmonyPatches/HealthAIUtility_FindBestMedicine.cs
@@ -2,6 +2,7 @@
 // HealthAIUtility_FindBestMedicine.cs
 // 2017-02-11
 
+using System.Linq;
 using HarmonyLib;
 using RimWorld;
 using Verse;
@@ -10,15 +11,46 @@
 namespace Pharmacist {
     [HarmonyPatch(typeof(HealthAIUtility), nameof(HealthAIUtility.FindBestMedicine))]
     public class HealthAIUtility_FindBestMedicine {
-        public static bool Prefix(Pawn healer, Pawn patient, ref Thing __result) {
+        public static bool Prefix(Pawn healer, Pawn patient, bool onlyUseInventory, ref Thing __result) {
+
             // get lowest of pawn care settings & pharmacy settings
             MedicalCareCategory pharmacistAdvice = PharmacistUtility.TendAdvice( patient );
-
             if (pharmacistAdvice <= MedicalCareCategory.NoMeds) {
                 __result = null;
                 return false;
             }
 
+            // check count required
+            int countRequired = Medicine.GetMedicineCountToFullyHeal(patient);
+            if (countRequired <= 0) {
+                __result = null;
+                return false;
+            }
+
+            float potencyGetter(Thing t) {
+                return t.def.GetStatValueAbstract(StatDefOf.MedicalPotency);
+            }
+            bool allowedPredicate(Thing m) {
+                return !m.IsForbidden(healer)
+                    && m.def.IsMedicine
+                    && pharmacistAdvice.AllowsMedicine(m.def)
+                    && healer.CanReserve(m, 10, 1);
+            }
+
+            // check pockets first
+            // note: vanilla actually selects the medicine with the _lowest_ potency,
+            // I have to assume that that is not intentional.
+            //
+            // thanks to KennethSammael for adding this check in the unofficial 1.3 update,
+            // this code is adapted from his changes.
+            __result = healer.inventory.innerContainer
+                .Where(allowedPredicate)
+                .MaxBy(potencyGetter);
+            if (__result is not null || onlyUseInventory) {
+                return false;
+            }
+
+            // search for best meds
             __result = GenClosest.ClosestThing_Global_Reachable(
                 patient.Position,
                 patient.Map,
@@ -26,9 +58,8 @@ public static bool Prefix(Pawn healer, Pawn patient, ref Thing __result) {
                 PathEndMode.ClosestTouch,
                 TraverseParms.For(healer),
                 9999f,
-                (m) => !m.IsForbidden(healer) && pharmacistAdvice.AllowsMedicine(m.def) && healer.CanReserve(m, 1),
-                (m) => m.def.GetStatValueAbstract(StatDefOf.MedicalPotency));
-
+                allowedPredicate,
+                potencyGetter);
             return false;
         }
     }
diff --git a/Source/HarmonyPatches/WorkGiver_DoBill_GetMedicalCareCategory.cs b/Source/HarmonyPatches/WorkGiver_DoBill_GetMedicalCareCategory.cs
index 063e226..2b60944 100644
--- a/Source/HarmonyPatches/WorkGiver_DoBill_GetMedicalCareCategory.cs
+++ b/Source/HarmonyPatches/WorkGiver_DoBill_GetMedicalCareCategory.cs
@@ -9,7 +9,7 @@ namespace Pharmacist.Properties {
     [HarmonyPatch(typeof(WorkGiver_DoBill), "GetMedicalCareCategory")]
     public static class WorkGiver_DoBill_GetMedicalCareCategory {
         public static bool Prefix(Thing billGiver, ref MedicalCareCategory __result) {
-            if (!(billGiver is Pawn pawn)) {
+            if (billGiver is not Pawn pawn) {
                 // because this is the fallback vanilla uses...
                 __result = MedicalCareCategory.Best;
             } else {
diff --git a/Source/Pharmacist.csproj b/Source/Pharmacist.csproj
index 9ef67b4..af26639 100644
--- a/Source/Pharmacist.csproj
+++ b/Source/Pharmacist.csproj
@@ -8,6 +8,7 @@
         <OutputPath>..\Assemblies\</OutputPath>
         <DebugType>portable</DebugType>
         <PostBuildEvent>mod update</PostBuildEvent>
+        <LangVersion>9</LangVersion>
     </PropertyGroup>
     <ItemGroup>
         <PackageReference Include="Krafs.Rimworld.Ref" Version="1.3.3087" />