diff --git a/os161-container/Dockerfile b/os161-container/Dockerfile
index 67bb4b0a0c7fe4b236e24155f572a46c8caafeb2..4945e7229159f5efb2014b7525046cad25c66b73 100644
--- a/os161-container/Dockerfile
+++ b/os161-container/Dockerfile
@@ -10,12 +10,16 @@ RUN mkdir -p /os161/tools/bin; \
     mkdir -p /os161/tools/share/man/man1; \
     mkdir -p /os161/tools/share/mk;
 
+# Install a newer version of config.guess with ARM support. Pin it to a specific commit for stability.
+ADD https://git.savannah.gnu.org/cgit/config.git/plain/config.guess?id=20403c5701973a4cbd7e0b4bbeb627fcd424a0f1 /tmp/config.guess
+RUN chmod +x /tmp/config.guess
 
 COPY dependencies/os161-binutils.tar.gz /binutils.tar.gz
 RUN mkdir /binutils-src; \
     tar -xf /binutils.tar.gz -C /binutils-src --strip-components 1
 WORKDIR /binutils-src
 
+RUN cp -f /tmp/config.guess .
 RUN find . -name '*.info' | xargs touch; \
     ./configure --nfp --disable-werror --target=mips-harvard-os161 --prefix=/os161/tools; \
     make -j 4 && make install; \
@@ -30,6 +34,7 @@ RUN mkdir /gcc-src; \
     tar -xf /gcc.tar.gz -C /gcc-src --strip-components 1
 WORKDIR /gcc-src
 
+RUN cp -f /tmp/config.guess .
 RUN CFLAGS="-std=gnu89" ./configure -nfp --disable-shared --disable-threads \
 	--disable-libmudflap --disable-libssp --target=mips-harvard-os161 --prefix=/os161/tools; \
     make -j 4 && make install; \
@@ -65,12 +70,14 @@ COPY dependencies/os161-gdb.tar.gz /os161-gdb.tar.gz
 RUN mkdir /os161-gdb/ && tar -xf /os161-gdb.tar.gz -C /os161-gdb --strip-components 1
 
 WORKDIR /os161-gdb
+RUN cp -f /tmp/config.guess .
 RUN CFLAGS="-std=gnu89" ./configure --target=mips-harvard-os161 --prefix=/os161/tools --disable-werror && \
     make && make install
 
 WORKDIR /
 RUN rm -rf /os161-gdb /os161-gdb.tar.gz
 
+RUN rm -f /tmp/config.guess
 RUN cd /os161/tools/bin && sh -c 'for i in mips-*; do ln -s /os161/tools/bin/$i /os161/tools/bin/cs350-`echo $i | cut -d- -f4-`; done'
 
 RUN python3 -m pip install -U prettytable