diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3a6d325..e382280 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -57,11 +57,11 @@ jobs:
       run: |
         python tools/make_example.py
         python tools/extract_code.py "bin/test.copapy" "bin/test.copapy.bin"
-        objdump --disassembler-color=on -D -b binary -m i386:x86-64 --adjust-vma=0x1000 bin/test.copapy.bin > bin/test.copapy.asm
+        objdump -D -b binary -m i386:x86-64 --adjust-vma=0x1000 bin/test.copapy.bin > bin/test.copapy.asm
         echo '<p>test.copapy.asm</p><pre>' >> $GITHUB_STEP_SUMMARY
         cat bin/test.copapy.asm >> $GITHUB_STEP_SUMMARY
         echo '</pre>' >> $GITHUB_STEP_SUMMARY
-        objdump --disassembler-color=on -d -j .text src/copapy/obj/stencils_x86_64_O3.o > bin/stencils_x86_64_O3.asm
+        objdump -d -j .text src/copapy/obj/stencils_x86_64_O3.o > bin/stencils_x86_64_O3.asm
         echo '<p>stencils_x86_64_O3.asm</p><pre>' >> $GITHUB_STEP_SUMMARY
         cat bin/stencils_x86_64_O3.asm >> $GITHUB_STEP_SUMMARY
         echo '</pre>' >> $GITHUB_STEP_SUMMARY