diff --git a/.circleci/config.yml b/.circleci/config.yml
index 8468fa13..d2bd27f9 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -199,24 +199,6 @@ references:
         only: /.*/
 
 jobs:
-  gcc_4_9_debug:
-    <<: *job_definition
-    environment:
-      CC: gcc-4.9
-      CXX: g++-4.9
-      BUILD_TOOLSET: gcc
-      APT_COMPILER_PACKAGE: "g++-4.9"
-      CXXFLAGS: ""
-      BUILD_TYPE: "Debug"
-  gcc_4_9_release:
-    <<: *job_definition
-    environment:
-      CC: gcc-4.9
-      CXX: g++-4.9
-      BUILD_TOOLSET: gcc
-      APT_COMPILER_PACKAGE: "g++-4.9"
-      CXXFLAGS: ""
-      BUILD_TYPE: "Release"
   gcc_5_debug:
     <<: *job_definition
     environment:
@@ -271,42 +253,6 @@ jobs:
       APT_COMPILER_PACKAGE: "g++-7"
       CXXFLAGS: ""
       BUILD_TYPE: "Release"
-  clang_3_7_debug:
-    <<: *job_definition
-    environment:
-      CC: clang-3.7
-      CXX: clang++-3.7
-      BUILD_TOOLSET: clang
-      APT_COMPILER_PACKAGE: clang-3.7
-      CXXFLAGS: ""
-      BUILD_TYPE: "Debug"
-  clang_3_7_release:
-    <<: *job_definition
-    environment:
-      CC: clang-3.7
-      CXX: clang++-3.7
-      BUILD_TOOLSET: clang
-      APT_COMPILER_PACKAGE: clang-3.7
-      CXXFLAGS: ""
-      BUILD_TYPE: "Release"
-  clang_3_8_debug:
-    <<: *job_definition
-    environment:
-      CC: clang-3.8
-      CXX: clang++-3.8
-      BUILD_TOOLSET: clang
-      APT_COMPILER_PACKAGE: clang-3.8
-      CXXFLAGS: ""
-      BUILD_TYPE: "Debug"
-  clang_3_8_release:
-    <<: *job_definition
-    environment:
-      CC: clang-3.8
-      CXX: clang++-3.8
-      BUILD_TOOLSET: clang
-      APT_COMPILER_PACKAGE: clang-3.8
-      CXXFLAGS: ""
-      BUILD_TYPE: "Release"
   clang_4_0_debug:
     <<: *job_definition
     environment:
@@ -380,10 +326,6 @@ workflows:
 
   build_and_test:
     jobs:
-    - gcc_4_9_debug:
-        <<: *enable_for_tags
-    - gcc_4_9_release:
-        <<: *enable_for_tags
     - gcc_5_debug:
         <<: *enable_for_tags
     - gcc_5_release:
@@ -396,14 +338,6 @@ workflows:
         <<: *enable_for_tags
     - gcc_7_release:
         <<: *enable_for_tags
-    - clang_3_7_debug:
-        <<: *enable_for_tags
-    - clang_3_7_release:
-        <<: *enable_for_tags
-    - clang_3_8_debug:
-        <<: *enable_for_tags
-    - clang_3_8_release:
-        <<: *enable_for_tags
     - clang_4_0_debug:
         <<: *enable_for_tags
     - clang_4_0_release:
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e6445124..54f2d464 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,8 +11,8 @@ project(cryfs)
 
 include(utils.cmake)
 
-require_gcc_version(4.8)
-require_clang_version(3.7)
+require_gcc_version(5.0)
+require_clang_version(4.0)
 
 # Default value is not to build test cases
 option(BUILD_TESTING "build test cases" OFF)
diff --git a/README.md b/README.md
index e924b823..4ae4f69e 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ Building from source
 Requirements
 ------------
   - Git (for getting the source code)
-  - GCC version >= 4.8 or Clang >= 3.7
+  - GCC version >= 5.0 or Clang >= 4.0
   - CMake version >= 3.0 
   - libcurl4 (including development headers)
   - Boost libraries version >= 1.56 (including development headers)