diff --git a/.appveyor.yml b/.appveyor.yml
index a4c523c..91cebe4 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -21,8 +21,8 @@ install:
   - conda config --set always_yes yes --set changeps1 no
   - conda update -q conda
   - conda info -a
-  - conda install cmake -c conda-forge
-  - conda install pytest numpy pybind11==2.4.3 xtensor==0.23.10 -c conda-forge
+  - conda install mamba -c conda-forge
+  - mamba install cmake pytest numpy pybind11 xtensor==0.24.0 -c conda-forge
   - "set PYTHONHOME=%MINICONDA%"
   - cmake -G "NMake Makefiles" -D CMAKE_INSTALL_PREFIX=%MINICONDA%\\Library -D BUILD_TESTS=ON -D PYTHON_EXECUTABLE=%MINICONDA%\\python.exe -DDOWNLOAD_GTEST=ON .
   - nmake test_xtensor_python
diff --git a/.azure-pipelines/azure-pipelines-linux-clang.yml b/.azure-pipelines/azure-pipelines-linux-clang.yml
index f1d6894..87d7592 100644
--- a/.azure-pipelines/azure-pipelines-linux-clang.yml
+++ b/.azure-pipelines/azure-pipelines-linux-clang.yml
@@ -2,10 +2,6 @@ jobs:
   - job: 'Linux_0'
     strategy:
       matrix:
-        clang_4:
-          llvm_version: '4.0'
-        clang_5:
-          llvm_version: '5.0'
         clang_6:
           llvm_version: '6.0'
         clang_7:
@@ -15,7 +11,7 @@ jobs:
         clang_9:
           llvm_version: '9'
     pool:
-      vmImage: ubuntu-16.04
+      vmImage: ubuntu-18.04
     variables:
       CC: clang-$(llvm_version)
       CXX: clang++-$(llvm_version)
diff --git a/.azure-pipelines/azure-pipelines-linux-gcc.yml b/.azure-pipelines/azure-pipelines-linux-gcc.yml
index 7b1eb9d..e0a6aa0 100644
--- a/.azure-pipelines/azure-pipelines-linux-gcc.yml
+++ b/.azure-pipelines/azure-pipelines-linux-gcc.yml
@@ -2,10 +2,6 @@ jobs:
   - job: 'Linux_1'
     strategy:
       matrix:
-        gcc_4:
-          gcc_version: '4.9'
-        gcc_5:
-          gcc_version: '5'
         gcc_6:
           gcc_version: '6'
         gcc_7:
@@ -15,7 +11,7 @@ jobs:
         gcc_9:
           gcc_version: '9'
     pool:
-      vmImage: ubuntu-16.04
+      vmImage: ubuntu-18.04
     variables:
       CC: gcc-$(gcc_version)
       CXX: g++-$(gcc_version)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 694ee0d..e1bd077 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,7 +32,7 @@ message(STATUS "xtensor-python v${${PROJECT_NAME}_VERSION}")
 # Dependencies
 # ============
 
-set(xtensor_REQUIRED_VERSION 0.21.2)
+set(xtensor_REQUIRED_VERSION 0.24.0)
 if(TARGET xtensor)
     set(xtensor_VERSION ${XTENSOR_VERSION_MAJOR}.${XTENSOR_VERSION_MINOR}.${XTENSOR_VERSION_PATCH})
     # Note: This is not SEMVER compatible comparison
diff --git a/environment-dev.yml b/environment-dev.yml
index 53809d5..6dff19f 100644
--- a/environment-dev.yml
+++ b/environment-dev.yml
@@ -5,7 +5,7 @@ dependencies:
   # Build dependencies
   - cmake
   # Host dependencies
-  - xtensor=0.23.10
+  - xtensor=0.24.0
   - numpy
   - pybind11=2.4.3
   # Test dependencies