diff --git a/.circleci/config.yml b/.circleci/config.yml
index 33865f9c8295..1c19258b8801 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -134,7 +134,7 @@ jobs:
           echo "export CRYSTAL_SHA1=$CIRCLE_SHA1" >> build.env
 
           # Which previous version use
-          export PREVIOUS_CRYSTAL_BASE_URL="https://github.com/crystal-lang/crystal/releases/download/1.2.2/crystal-1.2.2-1"
+          export PREVIOUS_CRYSTAL_BASE_URL="https://github.com/crystal-lang/crystal/releases/download/1.3.0/crystal-1.3.0-1"
           echo "export PREVIOUS_CRYSTAL_RELEASE_LINUX64_TARGZ=${PREVIOUS_CRYSTAL_BASE_URL}-linux-x86_64.tar.gz" >> build.env
           echo "export PREVIOUS_CRYSTAL_RELEASE_DARWIN_TARGZ=${PREVIOUS_CRYSTAL_BASE_URL}-darwin-universal.tar.gz" >> build.env
 
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index bd80ba439387..97d67289015b 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        crystal_bootstrap_version: [1.2.2]
+        crystal_bootstrap_version: [1.2.2, 1.3.0]
         include:
           # libffi is only available starting from the 1.2.2 build images
           - crystal_bootstrap_version: 1.0.0
diff --git a/.github/workflows/openssl.yml b/.github/workflows/openssl.yml
index 0d1636589289..38d396336733 100644
--- a/.github/workflows/openssl.yml
+++ b/.github/workflows/openssl.yml
@@ -6,7 +6,7 @@ jobs:
   openssl3:
     runs-on: ubuntu-latest
     name: "OpenSSL 3.0"
-    container: crystallang/crystal:1.2.2-alpine
+    container: crystallang/crystal:1.3.0-alpine
     steps:
       - name: Download Crystal source
         uses: actions/checkout@v2
@@ -23,7 +23,7 @@ jobs:
   openssl111:
     runs-on: ubuntu-latest
     name: "OpenSSL 1.1.1"
-    container: crystallang/crystal:1.2.2-alpine
+    container: crystallang/crystal:1.3.0-alpine
     steps:
       - name: Download Crystal source
         uses: actions/checkout@v2
@@ -36,7 +36,7 @@ jobs:
   libressl31:
     runs-on: ubuntu-latest
     name: "LibreSSL 3.1"
-    container: crystallang/crystal:1.2.2-alpine
+    container: crystallang/crystal:1.3.0-alpine
     steps:
       - name: Download Crystal source
         uses: actions/checkout@v2
@@ -51,7 +51,7 @@ jobs:
   libressl34:
     runs-on: ubuntu-latest
     name: "LibreSSL 3.4"
-    container: crystallang/crystal:1.2.2-alpine
+    container: crystallang/crystal:1.3.0-alpine
     steps:
       - name: Download Crystal source
         uses: actions/checkout@v2
diff --git a/.github/workflows/win.yml b/.github/workflows/win.yml
index 0890978d334c..9b3f9517a076 100644
--- a/.github/workflows/win.yml
+++ b/.github/workflows/win.yml
@@ -5,7 +5,7 @@ on: [push, pull_request]
 jobs:
   linux-job:
     runs-on: ubuntu-latest
-    container: crystallang/crystal:1.2.2-build
+    container: crystallang/crystal:1.3.0-build
     steps:
       - name: Download Crystal source
         uses: actions/checkout@v2
diff --git a/bin/ci b/bin/ci
index 0281f8f2aada..dd2cb5d301c3 100755
--- a/bin/ci
+++ b/bin/ci
@@ -135,8 +135,8 @@ format() {
 prepare_build() {
   on_linux verify_linux_environment
 
-  on_osx curl -L https://github.com/crystal-lang/crystal/releases/download/1.2.2/crystal-1.2.2-1-darwin-universal.tar.gz -o ~/crystal.tar.gz
-  on_osx 'pushd ~;gunzip -c ~/crystal.tar.gz | tar xopf -;mv crystal-1.2.2-1 crystal;popd'
+  on_osx curl -L https://github.com/crystal-lang/crystal/releases/download/1.3.0/crystal-1.3.0-1-darwin-universal.tar.gz -o ~/crystal.tar.gz
+  on_osx 'pushd ~;gunzip -c ~/crystal.tar.gz | tar xopf -;mv crystal-1.3.0-1 crystal;popd'
 
   # These commands may take a few minutes to run due to the large size of the repositories.
   # This restriction has been made on GitHub's request because updating shallow
@@ -189,7 +189,7 @@ with_build_env() {
 
   on_linux verify_linux_environment
 
-  export DOCKER_TEST_PREFIX="${DOCKER_TEST_PREFIX:=crystallang/crystal:1.2.2}"
+  export DOCKER_TEST_PREFIX="${DOCKER_TEST_PREFIX:=crystallang/crystal:1.3.0}"
 
   case $ARCH in
     x86_64)
diff --git a/shell.nix b/shell.nix
index c2222b12122b..2e4fbdcb8492 100644
--- a/shell.nix
+++ b/shell.nix
@@ -52,13 +52,13 @@ let
   # Hashes obtained using `nix-prefetch-url --unpack <url>`
   latestCrystalBinary = genericBinary ({
     x86_64-darwin = {
-      url = "https://github.com/crystal-lang/crystal/releases/download/1.2.2/crystal-1.2.2-1-darwin-universal.tar.gz";
-      sha256 = "sha256:1y7bcwl6jybg28sdd9xrgkxbz3ysdqn1jlgapi50avc47h30kgbb";
+      url = "https://github.com/crystal-lang/crystal/releases/download/1.3.0/crystal-1.3.0-1-darwin-universal.tar.gz";
+      sha256 = "sha256:0kyy2fpn5qcq9c8qrvv8mclb6qfr0cjm8w6gfhhym7f6bsbhrsx8";
     };
 
     x86_64-linux = {
-      url = "https://github.com/crystal-lang/crystal/releases/download/1.2.2/crystal-1.2.2-1-linux-x86_64.tar.gz";
-      sha256 = "sha256:1cxkyq7n2xw6h9c99h28c2ssf3viiw1vigb0w6l2rpnw4f55fbqz";
+      url = "https://github.com/crystal-lang/crystal/releases/download/1.3.0/crystal-1.3.0-1-darwin-universal.tar.gz";
+      sha256 = "sha256:0kyy2fpn5qcq9c8qrvv8mclb6qfr0cjm8w6gfhhym7f6bsbhrsx8";
     };
   }.${pkgs.stdenv.system});
 
diff --git a/src/VERSION b/src/VERSION
index f0bb29e76388..c3f0d2bbd2b8 100644
--- a/src/VERSION
+++ b/src/VERSION
@@ -1 +1 @@
-1.3.0
+1.4.0-dev