diff --git a/.azure-pipelines/windows-msbuild.bat b/.azure-pipelines/windows-msbuild.bat
index 3818f38e08..85fbb58f23 100644
--- a/.azure-pipelines/windows-msbuild.bat
+++ b/.azure-pipelines/windows-msbuild.bat
@@ -43,7 +43,7 @@ msbuild /target:dmd /p:Configuration=%CONFIGURATION% /p:Platform=%PLATFORM% %LDC
 %DMD% --version
 
 echo [STEP]: Building druntime
-make -j%N% -C "%DMD_DIR%\druntime" -f posix.mak MODEL=%MODEL% "DMD=%DMD%" "HOST_DMD=%HOST_DMD%" || exit /B 2
+make -j%N% -C "%DMD_DIR%\druntime" MODEL=%MODEL% "DMD=%DMD%" || exit /B 2
 
 echo [STEP]: Building phobos
 cd "%DMD_DIR%\..\phobos"
@@ -92,7 +92,7 @@ if not "%C_RUNTIME%" == "mingw" goto not_mingw
 
 echo [STEP]: Building and running druntime tests
 cd "%DMD_DIR%\druntime"
-make -j%N% -f posix.mak MODEL=%MODEL% "DMD=%DMD%" unittest || exit /B 5
+make -j%N% MODEL=%MODEL% "DMD=%DMD%" unittest || exit /B 5
 "%DM_MAKE%" -f win64.mak MODEL=%MODEL% "DMD=%DMD%" "VCDIR=%VCINSTALLDIR%." "CC=%MSVC_CC%" "MAKE=%DM_MAKE%" %DRUNTIME_TESTS% || exit /B 5
 
 echo [STEP]: Running DMD testsuite
diff --git a/.azure-pipelines/windows.sh b/.azure-pipelines/windows.sh
index 95741f1398..fb1954da8a 100644
--- a/.azure-pipelines/windows.sh
+++ b/.azure-pipelines/windows.sh
@@ -100,7 +100,7 @@ DMD_BIN_PATH="$DMD_DIR/generated/windows/release/$TOOL_MODEL/dmd.exe"
 
 LIBS_MAKE_ARGS=(-f "$MAKE_FILE" MODEL=$MODEL DMD="$DMD_BIN_PATH" VCDIR=. CC="$CC" AR="$AR" MAKE="$DM_MAKE")
 
-"$GNU_MAKE" -j$N -C "$DMD_DIR/druntime" -f posix.mak MODEL=$MODEL DMD="$DMD_BIN_PATH"
+"$GNU_MAKE" -j$N -C "$DMD_DIR/druntime" MODEL=$MODEL DMD="$DMD_BIN_PATH"
 
 cd "$DMD_DIR/../phobos"
 "$DM_MAKE" "${LIBS_MAKE_ARGS[@]}" DRUNTIME="$DMD_DIR\druntime" DRUNTIMELIB="$DMD_DIR/generated/windows/release/$MODEL/druntime.lib"
@@ -164,7 +164,7 @@ fi
 ################################################################################
 
 cd "$DMD_DIR/druntime"
-"$GNU_MAKE" -j$N -f posix.mak MODEL=$MODEL DMD="$DMD_BIN_PATH" unittest
+"$GNU_MAKE" -j$N MODEL=$MODEL DMD="$DMD_BIN_PATH" unittest
 "$DM_MAKE" "${LIBS_MAKE_ARGS[@]}" test_all
 
 ################################################################################
diff --git a/.circleci/run.sh b/.circleci/run.sh
index 6a50985b48..4d9b8517ab 100755
--- a/.circleci/run.sh
+++ b/.circleci/run.sh
@@ -117,7 +117,7 @@ coverage()
     dmd -g -od=generated -of=$builder compiler/src/build
     # build dmd, druntime, and phobos
     $builder MODEL=$MODEL HOST_DMD=$DMD BUILD=$BUILD all
-    make -j$N -C druntime -f posix.mak MODEL=$MODEL BUILD=$BUILD
+    make -j$N -C druntime MODEL=$MODEL BUILD=$BUILD
     make -j$N -C ../phobos -f posix.mak MODEL=$MODEL BUILD=$BUILD
 
     # save the built dmd as host compiler this time
@@ -189,7 +189,7 @@ test_cxx()
     source "$(CURL_USER_AGENT=\"$CURL_USER_AGENT\" bash ~/dlang/install.sh dmd-$HOST_DMD_VER --activate)"
     echo "Test CXX frontend.h header generation"
     ./compiler/src/build.d
-    make -j$N -C druntime -f posix.mak MODEL=$MODEL BUILD=$BUILD
+    make -j$N -C druntime MODEL=$MODEL BUILD=$BUILD
     make -j$N -C ../phobos -f posix.mak MODEL=$MODEL BUILD=$BUILD
     ./compiler/src/build.d cxx-headers-test
     deactivate
diff --git a/.github/workflows/runnable_cxx.yml b/.github/workflows/runnable_cxx.yml
index 9e29190a4b..b8abdaaaca 100644
--- a/.github/workflows/runnable_cxx.yml
+++ b/.github/workflows/runnable_cxx.yml
@@ -324,13 +324,13 @@ jobs:
       run: |
         # All hosts are 64 bits but let's be explicit
         ./dmd/compiler/src/build.d -j2 MODEL=64
-        make -C dmd/druntime -f posix.mak -j2 MODEL=64
+        make -C dmd/druntime -j2 MODEL=64
         make -C phobos   -f posix.mak -j2 MODEL=64
         # Both version can live side by side (they end up in a different directory)
         # However, since clang does not provide a multilib package, only test 32 bits with g++
         if [ ${{ matrix.compiler }} == "g++" ]; then
           ./dmd/compiler/src/build.d install -j2 MODEL=32
-          make -C dmd/druntime -f posix.mak install -j2 MODEL=32
+          make -C dmd/druntime install -j2 MODEL=32
           make -C phobos   -f posix.mak install -j2 MODEL=32
         fi
 
diff --git a/Makefile b/Makefile
index 1f04e93c30..b7a186f74d 100644
--- a/Makefile
+++ b/Makefile
@@ -57,7 +57,7 @@ clean:
 	rm -rf $(GENERATED)
 	cd compiler/test && rm -rf test_results *.lst trace.log trace.def
 	$(RM) tags
-	$(QUIET)$(MAKE) -C druntime -f posix.mak clean
+	$(QUIET)$(MAKE) -C druntime clean
 
 dmd: $(BUILD_EXE)
 	$(BUILD_EXE) $@
@@ -67,10 +67,10 @@ dmd-test: dmd druntime $(BUILD_EXE) $(RUN_EXE)
 	$(RUN_EXE) --environment
 
 druntime: dmd
-	$(QUIET)$(MAKE) -C druntime -f posix.mak
+	$(QUIET)$(MAKE) -C druntime
 
 druntime-test: dmd
-	$(QUIET)$(MAKE) -C druntime -f posix.mak unittest
+	$(QUIET)$(MAKE) -C druntime unittest
 
 test: dmd-test druntime-test
 
diff --git a/ci/run.sh b/ci/run.sh
index 79834769c1..490cc8f886 100755
--- a/ci/run.sh
+++ b/ci/run.sh
@@ -62,7 +62,7 @@ build() {
     $DMD compiler/src/build.d -ofgenerated/build
     generated/build -j$N MODEL=$MODEL HOST_DMD=$DMD DFLAGS="$CI_DFLAGS" BUILD=debug unittest
     generated/build -j$N MODEL=$MODEL HOST_DMD=$DMD DFLAGS="$CI_DFLAGS" ENABLE_RELEASE=1 dmd
-    make -j$N -C druntime -f posix.mak MODEL=$MODEL
+    make -j$N -C druntime MODEL=$MODEL
     make -j$N -C ../phobos -f posix.mak MODEL=$MODEL
     deactivate # deactivate host compiler
 }
@@ -114,7 +114,7 @@ test_dmd() {
 
 # build and run druntime unit tests
 test_druntime() {
-    make -j$N -C druntime -f posix.mak MODEL=$MODEL unittest
+    make -j$N -C druntime MODEL=$MODEL unittest
 }
 
 # build and run Phobos unit tests
diff --git a/druntime/posix.mak b/druntime/Makefile
similarity index 100%
rename from druntime/posix.mak
rename to druntime/Makefile