diff --git a/Pantograph/Delate.lean b/Pantograph/Delate.lean
index efb1008..b6e016c 100644
--- a/Pantograph/Delate.lean
+++ b/Pantograph/Delate.lean
@@ -122,7 +122,8 @@ partial def instantiateDelayedMVars (expr : Expr) : MetaM Expr :=
         return .visit (mkAppN assign args)
       else if let some { fvars, mvarIdPending } ← getDelayedMVarAssignment? mvarId then
         if ← isTracingEnabledFor `Pantograph.Delate then
-          let substTableStr := String.intercalate ", " $ Array.zipWith fvars args (λ fvar assign => s!"{fvar.fvarId!.name} := {assign}") |>.toList
+          let substTableStr := ",".intercalate $
+            Array.zipWith (λ fvar assign => s!"{fvar.fvarId!.name} := {assign}") fvars args |>.toList
           trace[Pantograph.Delate]"MD ?{mvarId.name} := ?{mvarIdPending.name} [{substTableStr}]"
 
         if args.size < fvars.size then
diff --git a/Pantograph/Environment.lean b/Pantograph/Environment.lean
index aa4dd03..8e552a3 100644
--- a/Pantograph/Environment.lean
+++ b/Pantograph/Environment.lean
@@ -91,7 +91,6 @@ def inspect (args: Protocol.EnvInspect) (options: @&Protocol.Options): CoreM (Pr
     isUnsafe := info.isUnsafe,
     value? := ← value?.mapM (λ v => serializeExpression options v |>.run'),
     publicName? := Lean.privateToUserName? name |>.map (·.toString),
-    -- BUG: Warning: getUsedConstants here will not include projections. This is a known bug.
     typeDependency? := if args.dependency?.getD false
       then .some <| type.getUsedConstants.map (λ n => serializeName n)
       else .none,
@@ -169,7 +168,7 @@ def addDecl (args: Protocol.EnvAdd): CoreM (Protocol.CR Protocol.EnvAddResult) :
   let (type, value) ← match ← tvM.run' (ctx := {}) |>.run' with
     | .ok t => pure t
     | .error e => return .error $ Protocol.errorExpr e
-  let constant := Lean.Declaration.defnDecl <| Lean.mkDefinitionValEx
+  let decl := Lean.Declaration.defnDecl <| Lean.mkDefinitionValEx
     (name := args.name.toName)
     (levelParams := [])
     (type := type)
@@ -177,13 +176,7 @@ def addDecl (args: Protocol.EnvAdd): CoreM (Protocol.CR Protocol.EnvAddResult) :
     (hints := Lean.mkReducibilityHintsRegularEx 1)
     (safety := Lean.DefinitionSafety.safe)
     (all := [])
-  let env' ← match env.addDecl (← getOptions) constant with
-    | .error e => do
-      let options ← Lean.MonadOptions.getOptions
-      let desc ← (e.toMessageData options).toString
-      return .error $ { error := "kernel", desc }
-    | .ok env' => pure env'
-  Lean.MonadEnv.modifyEnv (λ _ => env')
+  Lean.addDecl decl
   return .ok {}
 
 end Pantograph.Environment
diff --git a/Pantograph/Version.lean b/Pantograph/Version.lean
index a65274d..845d83f 100644
--- a/Pantograph/Version.lean
+++ b/Pantograph/Version.lean
@@ -1,6 +1,6 @@
 namespace Pantograph
 
 @[export pantograph_version]
-def version := "0.3.0-rc.1"
+def version := "0.3.0"
 
 end Pantograph
diff --git a/Test/Serial.lean b/Test/Serial.lean
index fcdc155..bd22d72 100644
--- a/Test/Serial.lean
+++ b/Test/Serial.lean
@@ -47,12 +47,8 @@ def test_environment_pickling : TestM Unit := do
       (hints := Lean.mkReducibilityHintsRegularEx 1)
       (safety := Lean.DefinitionSafety.safe)
       (all := [])
-    let env' ← match (← getEnv).addDecl (← getOptions) c with
-      | .error e => do
-        let error ← (e.toMessageData (← getOptions)).toString
-        throwError error
-      | .ok env' => pure env'
-    environmentPickle env' envPicklePath
+    addDecl c
+    environmentPickle (← getEnv) envPicklePath
 
   let _ ← runCoreM coreDst do
     let (env', _) ← environmentUnpickle envPicklePath
diff --git a/flake.lock b/flake.lock
index 2b9a841..11c740e 100644
--- a/flake.lock
+++ b/flake.lock
@@ -5,11 +5,11 @@
         "nixpkgs-lib": "nixpkgs-lib"
       },
       "locked": {
-        "lastModified": 1738453229,
-        "narHash": "sha256-7H9XgNiGLKN1G1CgRh0vUL4AheZSYzPm+zmZ7vxbJdo=",
+        "lastModified": 1741352980,
+        "narHash": "sha256-+u2UunDA4Cl5Fci3m7S643HzKmIDAe+fiXrLqYsR2fs=",
         "owner": "hercules-ci",
         "repo": "flake-parts",
-        "rev": "32ea77a06711b758da0ad9bd6a844c5740a87abd",
+        "rev": "f4330d22f1c5d2ba72d3d22df5597d123fdb60a9",
         "type": "github"
       },
       "original": {
@@ -44,11 +44,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1739073990,
-        "narHash": "sha256-VmLkZf4+1HWrIDB/JUlPOAmOlutR6XTFRhDzDYJcYZM=",
+        "lastModified": 1741472588,
+        "narHash": "sha256-XnMeMZKuspEphP+fEq4soc3PY7Nz+gsMPjlsXbobyrA=",
         "owner": "lenianiva",
         "repo": "lean4-nix",
-        "rev": "7a6faedc6c3ab35c42add15c354bf69542b9a6e6",
+        "rev": "cffeb67d58e02b50ccb9acd51b0212dc653ed6ce",
         "type": "github"
       },
       "original": {
@@ -59,11 +59,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1741332913,
-        "narHash": "sha256-ri1e8ZliWS3Jnp9yqpKApHaOo7KBN33W8ECAKA4teAQ=",
+        "lastModified": 1742751704,
+        "narHash": "sha256-rBfc+H1dDBUQ2mgVITMGBPI1PGuCznf9rcWX/XIULyE=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "20755fa05115c84be00b04690630cb38f0a203ad",
+        "rev": "f0946fa5f1fb876a9dc2e1850d9d3a4e3f914092",
         "type": "github"
       },
       "original": {
@@ -75,14 +75,17 @@
     },
     "nixpkgs-lib": {
       "locked": {
-        "lastModified": 1738452942,
-        "narHash": "sha256-vJzFZGaCpnmo7I6i416HaBLpC+hvcURh/BQwROcGIp8=",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/072a6db25e947df2f31aab9eccd0ab75d5b2da11.tar.gz"
+        "lastModified": 1740877520,
+        "narHash": "sha256-oiwv/ZK/2FhGxrCkQkB83i7GnWXPPLzoqFHpDD3uYpk=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "147dee35aab2193b174e4c0868bd80ead5ce755c",
+        "type": "github"
       },
       "original": {
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/072a6db25e947df2f31aab9eccd0ab75d5b2da11.tar.gz"
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
       }
     },
     "nixpkgs-lib_2": {
diff --git a/lean-toolchain b/lean-toolchain
index 2586f88..5499a24 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:v4.16.0
+leanprover/lean4:v4.17.0