diff --git a/Makefile.am b/Makefile.am
index 3fda76704..9839bb50a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -4,21 +4,22 @@ SUBDIRS = src man tests
 DIST_SUBDIRS = src man tests
 
 EXTRA_DIST = FAQ autogen.sh Stuarts_Poly_Notes  \
-		ANALYSES BUGS AUTHORS INSTALL \
-		DEVICES INTERNALS NEWS README README.tcl README.optran\
-		README.shared-xspice README.vdmos README_OSDI.md\
-		README_OSDI_howto README.cpl-gc README.utf8 \
-		examples m4 visualc \
-		cross-compile.sh cross-compile-shared.sh \
-		compile_min.sh compile_linux.sh compile_min_shared.sh \
-		compile_linux_shared.sh compile_cyg_make_short_check_64.sh \
-		compile_macos_clang.sh compile_macos_gcc.sh \
-		compile_linux_dist.sh ngspice.pc.in .gitignore
+        ANALYSES BUGS AUTHORS INSTALL \
+        DEVICES INTERNALS NEWS README README.tcl README.optran\
+        README.shared-xspice README.vdmos README_OSDI.md\
+        README_OSDI_howto README.cpl-gc README.utf8 \
+        examples m4 visualc Dockerfile \
+        cross-compile.sh cross-compile-shared.sh \
+        compile_min.sh compile_linux.sh compile_min_shared.sh \
+        compile_linux_shared.sh compile_cyg_make_short_check_64.sh \
+        compile_macos_clang.sh compile_macos_gcc.sh compile_macos_shared.sh \
+        compile_macos_clang_M2.sh compile_macos_clang_M2_shared.sh
+        compile_linux_dist.sh ngspice.pc.in .gitignore
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 ar-lib compile config.guess \
-			src/include/ngspice/config.h.in config.sub configure install-sh \
-			missing mkinstalldirs stamp-h.in ltconfig \
-			ltmain.sh depcomp ylwrap ngspice.pc
+            src/include/ngspice/config.h.in config.sub configure install-sh \
+            missing mkinstalldirs stamp-h.in ltconfig \
+            ltmain.sh depcomp ylwrap ngspice.pc
 
 ACLOCAL_AMFLAGS = -I m4
 
@@ -28,6 +29,6 @@ pkgconfig_DATA = ngspice.pc
 endif SHARED_MODULE
 
 mrproper: maintainer-clean
-	rm -f `find $(top_srcdir) -type f -name "*~" -print`
-	rm -f `find $(top_srcdir) -type f -name "*.orig" -print`
-	rm -f `find $(top_srcdir) -type f -name "*.rej" -print`
+    rm -f `find $(top_srcdir) -type f -name "*~" -print`
+    rm -f `find $(top_srcdir) -type f -name "*.orig" -print`
+    rm -f `find $(top_srcdir) -type f -name "*.rej" -print`