diff --git a/.github/problem-matchers/gcc.json b/.github/problem-matchers/gcc.json
new file mode 100644
index 00000000000..e43b91c6ff0
--- /dev/null
+++ b/.github/problem-matchers/gcc.json
@@ -0,0 +1,17 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "gcc-problem-matcher",
+            "pattern": [
+                {
+                    "regexp": "^(?:(?:\\.\\.?)?\\/)?(?:icinga2\\/)?(.*?):(\\d+):(\\d*):?\\s+(?:fatal\\s+)?(warning|error):\\s+(.*)$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3,
+                    "severity": 4,
+                    "message": 5
+                }
+            ]
+        }
+    ]
+}
diff --git a/.github/problem-matchers/msvc.json b/.github/problem-matchers/msvc.json
new file mode 100644
index 00000000000..ba0aa32a4ee
--- /dev/null
+++ b/.github/problem-matchers/msvc.json
@@ -0,0 +1,49 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "msvc-problem-matcher",
+            "pattern": [
+                {
+                    "regexp": "^([^\\s].*icinga2.*)\\((\\d+),?(\\d+)?(?:,\\d+,\\d+)?\\):\\s(error|warning|info)\\s(\\w{1,2}\\d+):\\s([^\\s].*?)\\s\\[(.*)\\]$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3,
+                    "severity": 4,
+                    "code": 5,
+                    "message": 6,
+                    "fromPath": 7
+                }
+            ]
+        },
+        {
+            "owner": "msvc-template-problem-matcher",
+            "pattern": [
+                {
+                    "regexp": "^(?:[^\\s].*Microsoft.*)\\(\\d+,?\\d+?(?:,\\d+,\\d+)?\\):\\s(error|warning|info)\\s(\\w{1,2}\\d+):\\s([^\\s].*?)\\s\\[(.*)\\]$",
+                    "severity": 1,
+                    "code": 2,
+                    "message": 3,
+                    "fromPath": 4
+                },
+                {
+                    "regexp": "^\\s*(?:[^\\s].*Microsoft.*)\\(\\d+,?\\d+?(?:,\\d+,\\d+)?\\):.*$"
+                },
+                {
+                    "regexp": "^\\s*\\(compiling source file '.*?'\\)$"
+                },
+                {
+                    "regexp": "^\\s*(?:[^\\s].*Microsoft.*)\\(\\d+,?\\d+?(?:,\\d+,\\d+)?\\):.*$"
+                },
+                {
+                    "regexp": "^\\s+the template instantiation context \\(the oldest one first\\) is$"
+                },
+                {
+                    "regexp": "^\\s*([^\\s].*icinga2.*)\\((\\d+),?(\\d+)?(?:,\\d+,\\d+)?\\):$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3
+                }
+            ]
+        }
+    ]
+}
diff --git a/.github/workflows/linux.bash b/.github/workflows/linux.bash
index d0f0a16b510..dffe4c45664 100755
--- a/.github/workflows/linux.bash
+++ b/.github/workflows/linux.bash
@@ -5,6 +5,11 @@ export PATH="/usr/lib/ccache/bin:/usr/lib/ccache:/usr/lib64/ccache:$PATH"
 export CCACHE_DIR=/icinga2/ccache
 export CTEST_OUTPUT_ON_FAILURE=1
 CMAKE_OPTS=()
+# -Wstringop-overflow is notorious for false positives and has been a problem for years.
+# See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88443
+# -Wtemplate-id-cdtor leaks from using the generated headers. We should reenable this once
+# we're considering moving to C++20 and/or the -ti.hpp files are generated differently.
+WARN_FLAGS="-Wall -Wextra -Wno-template-id-cdtor -Wno-stringop-overflow"
 
 case "$DISTRO" in
   alpine:*)
@@ -28,7 +33,7 @@ case "$DISTRO" in
     (
       cd boost_1_69_0
       ./bootstrap.sh --with-libraries=context,coroutine,date_time,filesystem,iostreams,program_options,regex,system,test,thread
-      ./b2
+      ./b2 define=BOOST_COROUTINES_NO_DEPRECATION_WARNING
     )
 
     ln -vs /usr/bin/cmake3 /usr/local/bin/cmake
@@ -79,14 +84,21 @@ esac
 
 case "$DISTRO" in
   alpine:*)
-    CMAKE_OPTS+=(-DUSE_SYSTEMD=OFF -DICINGA2_WITH_MYSQL=OFF -DICINGA2_WITH_PGSQL=OFF)
+    CMAKE_OPTS+=(
+      -DUSE_SYSTEMD=OFF
+      -DICINGA2_WITH_MYSQL=OFF
+      -DICINGA2_WITH_PGSQL=OFF
+      -DCMAKE_{C,CXX}_FLAGS="${WARN_FLAGS}"
+    )
     ;;
   debian:*|ubuntu:*)
     CMAKE_OPTS+=(-DICINGA2_LTO_BUILD=ON)
     source <(dpkg-buildflags --export=sh)
+    export CFLAGS="${CFLAGS} ${WARN_FLAGS}"
+    export CXXFLAGS="${CXXFLAGS} ${WARN_FLAGS}"
     ;;
   *)
-    CMAKE_OPTS+=(-DCMAKE_{C,CXX}_FLAGS="$(rpm -E '%{optflags} %{?march_flag}')")
+    CMAKE_OPTS+=(-DCMAKE_{C,CXX}_FLAGS="$(rpm -E '%{optflags} %{?march_flag}') ${WARN_FLAGS}")
     export LDFLAGS="$(rpm -E '%{?build_ldflags}')"
     ;;
 esac
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index ac09815deb0..8fd8c080f9a 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -69,6 +69,9 @@ jobs:
       - name: Checkout HEAD
         uses: actions/checkout@v5
 
+      - name: Turn on Problem Matcher
+        run: echo "::add-matcher::.github/problem-matchers/gcc.json"
+
       - name: Restore/backup ccache
         uses: actions/cache@v4
         with:
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index be5ffe25e29..3dd237ee67e 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -38,6 +38,10 @@ jobs:
           Set-PSDebug -Trace 1
           & .\doc\win-dev.ps1
 
+      - name: Turn on Problem Matcher
+        run: |
+          Write-Host "::add-matcher::.github/problem-matchers/msvc.json"
+
       - name: Binary
         run: |
           Set-PSDebug -Trace 1
diff --git a/test/base-stacktrace.cpp b/test/base-stacktrace.cpp
index f0b87e2cf1c..ecee54a1ffe 100644
--- a/test/base-stacktrace.cpp
+++ b/test/base-stacktrace.cpp
@@ -20,12 +20,13 @@ using namespace icinga;
  *  should be printed. If it looks somewhat meaningful, you can probably ignore a failure of this test case.
  */
 
+#ifndef _MSC_VER
 #pragma GCC push_options
 #pragma GCC optimize ("O0")
 #pragma clang optimize off
-#ifdef _MSVC_VER
+#else /* _MSC_VER */
 #pragma optimize("", off)
-#endif /* _MSVC_VER */
+#endif /* _MSC_VER */
 
 BOOST_AUTO_TEST_SUITE(base_stacktrace)
 
@@ -65,8 +66,9 @@ BOOST_AUTO_TEST_CASE(stacktrace)
 
 BOOST_AUTO_TEST_SUITE_END()
 
+#ifndef _MSC_VER
 #pragma GCC pop_options
 #pragma clang optimize on
-#ifdef _MSVC_VER
+#else /* _MSC_VER */
 #pragma optimize("", on)
-#endif /* _MSVC_VER */
+#endif /* _MSC_VER */
diff --git a/third-party/mmatch/CMakeLists.txt b/third-party/mmatch/CMakeLists.txt
index f48e0739f04..4a8da1ed630 100644
--- a/third-party/mmatch/CMakeLists.txt
+++ b/third-party/mmatch/CMakeLists.txt
@@ -6,6 +6,13 @@ set(mmatch_SOURCES
 
 add_library(mmatch OBJECT ${mmatch_SOURCES})
 
+if(NOT MSVC)
+  target_compile_options(mmatch
+    PRIVATE
+    -Wno-implicit-fallthrough
+  )
+endif()
+
 set_target_properties(
   mmatch PROPERTIES
   FOLDER Lib
diff --git a/third-party/utf8cpp/extern/ftest b/third-party/utf8cpp/extern/ftest
deleted file mode 160000
index c4ad4af0946..00000000000
--- a/third-party/utf8cpp/extern/ftest
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit c4ad4af0946b73ce1a40cbc72205d15d196c7e06
diff --git a/tools/mkclass/classcompiler.cpp b/tools/mkclass/classcompiler.cpp
index 7559228169b..9a9f9b63388 100644
--- a/tools/mkclass/classcompiler.cpp
+++ b/tools/mkclass/classcompiler.cpp
@@ -1482,6 +1482,10 @@ void ClassCompiler::CompileStream(const std::string& path, std::istream& input,
 		<< "#pragma warning( push )" << std::endl
 		<< "#pragma warning( disable : 4244 )" << std::endl
 		<< "#pragma warning( disable : 4800 )" << std::endl
+		<< "#else /* _MSC_VER */" << std::endl
+		<< "#pragma GCC diagnostic push" << std::endl
+		<< "#pragma GCC diagnostic ignored \"-Wunused-parameter\"" << std::endl
+		<< "#pragma GCC diagnostic ignored \"-Wunused-variable\"" << std::endl
 		<< "#endif /* _MSC_VER */" << std::endl << std::endl;
 
 
@@ -1492,5 +1496,7 @@ void ClassCompiler::CompileStream(const std::string& path, std::istream& input,
 
 	oimpl << "#ifdef _MSC_VER" << std::endl
 		<< "#pragma warning ( pop )" << std::endl
+		<< "#else /* _MSC_VER */" << std::endl
+		<< "#pragma GCC diagnostic pop" << std::endl
 		<< "#endif /* _MSC_VER */" << std::endl;
 }