diff --git a/.github/workflows/build-macos.yml b/.github/workflows/build-macos.yml
index f457cc687c..846b18a9a3 100644
--- a/.github/workflows/build-macos.yml
+++ b/.github/workflows/build-macos.yml
@@ -40,7 +40,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Restore LLVM source cache
         uses: actions/cache/restore@v5
@@ -71,7 +71,7 @@ jobs:
         uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
-          key: llvm-build-20-${{ matrix.os }}-v2
+          key: llvm-build-20-${{ matrix.os }}-v3
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -131,7 +131,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Build TinyGo (LLVM ${{ matrix.version }})
         run: go install -tags=llvm${{ matrix.version }}
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index c6daaba052..19c8e5145a 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -23,7 +23,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Run go mod tidy
         run: go mod tidy
@@ -36,7 +36,7 @@ jobs:
     # statically linked binary.
     runs-on: ubuntu-latest
     container:
-      image: golang:1.26-alpine
+      image: golang:1.27rc1-alpine
     outputs:
       version: ${{ steps.version.outputs.version }}
     steps:
@@ -91,7 +91,7 @@ jobs:
         uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
-          key: llvm-build-20-linux-alpine-v2
+          key: llvm-build-20-linux-alpine-v3
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -115,7 +115,7 @@ jobs:
         uses: actions/cache@v5
         id: cache-binaryen
         with:
-          key: binaryen-linux-alpine-v2
+          key: binaryen-linux-alpine-v3
           path: build/wasm-opt
       - name: Build Binaryen
         if: steps.cache-binaryen.outputs.cache-hit != 'true'
@@ -160,7 +160,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Install wasmtime
         uses: bytecodealliance/actions/wasmtime/setup@v1
@@ -204,7 +204,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Install Node.js
         uses: actions/setup-node@v6
@@ -245,7 +245,7 @@ jobs:
         uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
-          key: llvm-build-20-linux-asserts-v1
+          key: llvm-build-20-linux-asserts-v2
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -323,7 +323,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Restore LLVM source cache
         uses: actions/cache/restore@v5
@@ -354,7 +354,7 @@ jobs:
         uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
-          key: llvm-build-20-linux-${{ matrix.goarch }}-v1
+          key: llvm-build-20-linux-${{ matrix.goarch }}-v2
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -378,7 +378,7 @@ jobs:
         uses: actions/cache@v5
         id: cache-binaryen
         with:
-          key: binaryen-linux-${{ matrix.goarch }}-v4
+          key: binaryen-linux-${{ matrix.goarch }}-v5
           path: build/wasm-opt
       - name: Build Binaryen
         if: steps.cache-binaryen.outputs.cache-hit != 'true'
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index f4e0308e51..a8285e046c 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -34,7 +34,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Restore cached LLVM source
         uses: actions/cache/restore@v5
@@ -65,7 +65,7 @@ jobs:
         uses: actions/cache/restore@v5
         id: cache-llvm-build
         with:
-          key: llvm-build-20-windows-v4
+          key: llvm-build-20-windows-v5
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -129,7 +129,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Download TinyGo build
         uses: actions/download-artifact@v8
@@ -150,7 +150,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Download TinyGo build
         uses: actions/download-artifact@v8
@@ -176,7 +176,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26.4'
+          go-version: '1.27.0-rc.1'
           cache: true
       - name: Download TinyGo build
         uses: actions/download-artifact@v8
diff --git a/Dockerfile b/Dockerfile
index 1fe6d2d74e..23ab6ed182 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # tinygo-llvm stage obtains the llvm source for TinyGo
-FROM golang:1.26 AS tinygo-llvm
+FROM golang:1.27rc1 AS tinygo-llvm
 
 RUN apt-get update && \
     apt-get install -y apt-utils make cmake clang-17 ninja-build && \
@@ -33,7 +33,7 @@ RUN cd /tinygo/ && \
 
 # tinygo-compiler copies the compiler build over to a base Go container (without
 # all the build tools etc).
-FROM golang:1.26 AS tinygo-compiler
+FROM golang:1.27rc1 AS tinygo-compiler
 
 # Copy tinygo build.
 COPY --from=tinygo-compiler-build /tinygo/build/release/tinygo /tinygo
diff --git a/src/runtime/os_darwin_go126.go b/src/runtime/os_darwin_go126.go
index d676482ca8..c013f02a87 100644
--- a/src/runtime/os_darwin_go126.go
+++ b/src/runtime/os_darwin_go126.go
@@ -1,4 +1,4 @@
-//go:build darwin && go1.26
+//go:build darwin && (go1.26 || go1.27)
 
 package runtime
 
diff --git a/src/runtime/runtime_windows_go126.go b/src/runtime/runtime_windows_go126.go
index 8918e49ef5..f7bd21ea0a 100644
--- a/src/runtime/runtime_windows_go126.go
+++ b/src/runtime/runtime_windows_go126.go
@@ -1,4 +1,4 @@
-//go:build windows && go1.26
+//go:build windows && (go1.26 || go1.27)
 
 package runtime