diff --git a/.circleci/config.yml b/.circleci/config.yml
index bfd1adc1d7..d636222c32 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -29,7 +29,7 @@ workflows:
 jobs:
   package_schema:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     steps:
       - checkout
       - run:
@@ -37,7 +37,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version; rustup target list --installed
       - restore_cache:
           keys:
-            - cargocache-v2-package_schema-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-package_schema-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Build
           working_directory: ~/project/packages/schema
@@ -52,11 +52,11 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: cargocache-v2-package_schema-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-package_schema-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   package_std:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     steps:
       - checkout
       - run:
@@ -64,7 +64,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version; rustup target list --installed
       - restore_cache:
           keys:
-            - cargocache-v2-package_std-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-package_std-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -111,11 +111,11 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: cargocache-v2-package_std-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-package_std-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   package_storage:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     steps:
       - checkout
       - run:
@@ -123,7 +123,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version; rustup target list --installed
       - restore_cache:
           keys:
-            - cargocache-v2-package_storage-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-package_storage-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Build library for native target
           working_directory: ~/project/packages/storage
@@ -142,11 +142,11 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: cargocache-v2-package_storage-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-package_storage-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   package_vm_cranelift:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     steps:
       - checkout
       - run:
@@ -157,7 +157,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version; rustup target list --installed
       - restore_cache:
           keys:
-            - cargocache-v2-package_vm_cranelift-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-package_vm_cranelift-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Build
           working_directory: ~/project/packages/vm
@@ -172,7 +172,7 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: cargocache-v2-package_vm_cranelift-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-package_vm_cranelift-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   package_vm_singlepass:
     docker:
@@ -214,7 +214,7 @@ jobs:
 
   contract_burner:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     working_directory: ~/cosmwasm/contracts/burner
     steps:
       - checkout:
@@ -224,7 +224,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version
       - restore_cache:
           keys:
-            - cargocache-v2-contract_burner-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-contract_burner-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -259,11 +259,11 @@ jobs:
             - target/wasm32-unknown-unknown/release/.fingerprint
             - target/wasm32-unknown-unknown/release/build
             - target/wasm32-unknown-unknown/release/deps
-          key: cargocache-v2-contract_burner-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-contract_burner-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   contract_hackatom:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     working_directory: ~/cosmwasm/contracts/hackatom
     steps:
       - checkout:
@@ -273,7 +273,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version
       - restore_cache:
           keys:
-            - cargocache-v2-contract_hackatom-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-contract_hackatom-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -308,7 +308,7 @@ jobs:
             - target/wasm32-unknown-unknown/release/.fingerprint
             - target/wasm32-unknown-unknown/release/build
             - target/wasm32-unknown-unknown/release/deps
-          key: cargocache-v2-contract_hackatom-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-contract_hackatom-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   # In this job we use singlepass as the VM to execute integration tests. This requires Rust nightly.
   # Avoid duplicating generic checks like unit tests or schema generation – they belong in the generic hackatom job.
@@ -347,7 +347,7 @@ jobs:
 
   contract_queue:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     working_directory: ~/cosmwasm/contracts/queue
     steps:
       - checkout:
@@ -357,7 +357,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version
       - restore_cache:
           keys:
-            - cargocache-v2-contract_queue-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-contract_queue-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -392,11 +392,11 @@ jobs:
             - target/wasm32-unknown-unknown/release/.fingerprint
             - target/wasm32-unknown-unknown/release/build
             - target/wasm32-unknown-unknown/release/deps
-          key: cargocache-v2-contract_queue-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-contract_queue-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   contract_reflect:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     working_directory: ~/cosmwasm/contracts/reflect
     steps:
       - checkout:
@@ -406,7 +406,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version
       - restore_cache:
           keys:
-            - cargocache-v2-contract_reflect-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-contract_reflect-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -441,11 +441,11 @@ jobs:
             - target/wasm32-unknown-unknown/release/.fingerprint
             - target/wasm32-unknown-unknown/release/build
             - target/wasm32-unknown-unknown/release/deps
-          key: cargocache-v2-contract_reflect-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-contract_reflect-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   contract_staking:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     working_directory: ~/cosmwasm/contracts/staking
     steps:
       - checkout:
@@ -455,7 +455,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version
       - restore_cache:
           keys:
-            - cargocache-v2-contract_staking-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-contract_staking-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -490,11 +490,11 @@ jobs:
             - target/wasm32-unknown-unknown/release/.fingerprint
             - target/wasm32-unknown-unknown/release/build
             - target/wasm32-unknown-unknown/release/deps
-          key: cargocache-v2-contract_staking-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-contract_staking-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   fmt:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     steps:
       - checkout
       - run:
@@ -502,7 +502,7 @@ jobs:
           command: rustc --version; cargo --version; rustup --version; rustup target list --installed
       - restore_cache:
           keys:
-            - cargocache-v2-fmt-rust:1.44.1-{{ checksum "Cargo.lock" }}
+            - cargocache-v2-fmt-rust:1.45.2-{{ checksum "Cargo.lock" }}
       - run:
           name: Add rustfmt component
           command: rustup component add rustfmt
@@ -535,14 +535,14 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: cargocache-v2-fmt-rust:1.44.1-{{ checksum "Cargo.lock" }}
+          key: cargocache-v2-fmt-rust:1.45.2-{{ checksum "Cargo.lock" }}
 
   clippy:
     docker:
-      - image: rust:1.44.1
+      - image: rust:1.45.2
     environment:
       # Make sure to choose version with clippy present: https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu.html
-      NIGHTLY_TOOLCHAIN: nightly-2020-05-26
+      NIGHTLY_TOOLCHAIN: nightly-2020-09-08
     steps:
       - checkout
       - run:
@@ -559,7 +559,7 @@ jobs:
           command: rustc +$NIGHTLY_TOOLCHAIN --version && cargo +$NIGHTLY_TOOLCHAIN --version
       - restore_cache:
           keys:
-            - cargocache-v2-clippy-rust:1.44.1-{{ checksum "Cargo.lock" }}-{{ checksum "contracts/burner/Cargo.lock" }}-{{ checksum "contracts/hackatom/Cargo.lock" }}-{{ checksum "contracts/queue/Cargo.lock" }}-{{ checksum "contracts/reflect/Cargo.lock" }}-{{ checksum "contracts/staking/Cargo.lock" }}
+            - cargocache-v2-clippy-rust:1.45.2-{{ checksum "Cargo.lock" }}-{{ checksum "contracts/burner/Cargo.lock" }}-{{ checksum "contracts/hackatom/Cargo.lock" }}-{{ checksum "contracts/queue/Cargo.lock" }}-{{ checksum "contracts/reflect/Cargo.lock" }}-{{ checksum "contracts/staking/Cargo.lock" }}
       - run:
           name: Add clippy component
           command: rustup component add clippy
@@ -646,7 +646,7 @@ jobs:
             - contracts/staking/target/debug/.fingerprint
             - contracts/staking/target/debug/build
             - contracts/staking/target/debug/deps
-          key: cargocache-v2-clippy-rust:1.44.1-{{ checksum "Cargo.lock" }}-{{ checksum "contracts/burner/Cargo.lock" }}-{{ checksum "contracts/hackatom/Cargo.lock" }}-{{ checksum "contracts/queue/Cargo.lock" }}-{{ checksum "contracts/reflect/Cargo.lock" }}-{{ checksum "contracts/staking/Cargo.lock" }}
+          key: cargocache-v2-clippy-rust:1.45.2-{{ checksum "Cargo.lock" }}-{{ checksum "contracts/burner/Cargo.lock" }}-{{ checksum "contracts/hackatom/Cargo.lock" }}-{{ checksum "contracts/queue/Cargo.lock" }}-{{ checksum "contracts/reflect/Cargo.lock" }}-{{ checksum "contracts/staking/Cargo.lock" }}
 
   # This job roughly follows the instructions from https://circleci.com/blog/publishing-to-github-releases-via-circleci/
   build_and_upload_devcontracts:
@@ -677,7 +677,7 @@ jobs:
             for contract_dir in ./contracts/*/; do
               name=$(basename $contract_dir)
               echo "Building $name ..."
-              docker run --volumes-from with_code cosmwasm/rust-optimizer:0.9.0 ./contracts/$name
+              docker run --volumes-from with_code cosmwasm/rust-optimizer:0.9.1 ./contracts/$name
               docker cp with_code:/code/contracts/$name/contract.wasm ./artifacts/$name.wasm
             done
       - run:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 74687d6f36..b225ca1b69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## 0.11.0 (unreleased)
 
+**all**
+
+- Drop support for Rust versions lower than 1.45.2.
+
 **cosmwasm-std**
 
 - Add `time_nanos` to `BlockInfo` allowing access to high precision block times.
diff --git a/contracts/README.md b/contracts/README.md
index 9d0ed200a5..6ce9e54e4e 100644
--- a/contracts/README.md
+++ b/contracts/README.md
@@ -17,25 +17,25 @@ To rebuild all contracts as part of a release use the following commands:
 docker run --rm -v "$(pwd)":/code \
   --mount type=volume,source="devcontract_cache_burner",target=/code/contracts/burner/target \
   --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
-  cosmwasm/rust-optimizer:0.9.0 ./contracts/burner
+  cosmwasm/rust-optimizer:0.9.1 ./contracts/burner
 
 docker run --rm -v "$(pwd)":/code \
   --mount type=volume,source="devcontract_cache_hackatom",target=/code/contracts/hackatom/target \
   --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
-  cosmwasm/rust-optimizer:0.9.0 ./contracts/hackatom
+  cosmwasm/rust-optimizer:0.9.1 ./contracts/hackatom
 
 docker run --rm -v "$(pwd)":/code \
   --mount type=volume,source="devcontract_cache_queue",target=/code/contracts/queue/target \
   --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
-  cosmwasm/rust-optimizer:0.9.0 ./contracts/queue
+  cosmwasm/rust-optimizer:0.9.1 ./contracts/queue
 
 docker run --rm -v "$(pwd)":/code \
   --mount type=volume,source="devcontract_cache_reflect",target=/code/contracts/reflect/target \
   --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
-  cosmwasm/rust-optimizer:0.9.0 ./contracts/reflect
+  cosmwasm/rust-optimizer:0.9.1 ./contracts/reflect
 
 docker run --rm -v "$(pwd)":/code \
   --mount type=volume,source="devcontract_cache_staking",target=/code/contracts/staking/target \
   --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
-  cosmwasm/rust-optimizer:0.9.0 ./contracts/staking
+  cosmwasm/rust-optimizer:0.9.1 ./contracts/staking
 ```
diff --git a/packages/vm/README.md b/packages/vm/README.md
index 72cc24a765..42c5e89975 100644
--- a/packages/vm/README.md
+++ b/packages/vm/README.md
@@ -23,7 +23,7 @@ To rebuild the test contracts, go to the repo root and do
 docker run --rm -v "$(pwd)":/code \
   --mount type=volume,source="devcontract_cache_hackatom",target=/code/contracts/hackatom/target \
   --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
-  cosmwasm/rust-optimizer:0.9.0 ./contracts/hackatom \
+  cosmwasm/rust-optimizer:0.9.1 ./contracts/hackatom \
   && cp contracts/hackatom/contract.wasm packages/vm/testdata/contract_0.11.wasm
 ```