diff --git a/cmake/AddCompilerFlags.cmake b/cmake/AddCompilerFlags.cmake
index d34df72..40b5185 100644
--- a/cmake/AddCompilerFlags.cmake
+++ b/cmake/AddCompilerFlags.cmake
@@ -88,13 +88,17 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|amd64|AMD64)$" AND NOT WIN32 AND NOT
         # future-proof against the next GCC version autovectorizing
         # beyond AVX-512. See references/avx-512-sigill-build-fix.md
         # for the full diagnosis recipe.
+        # NB: -mno-avx512*4fmaps / -mno-avx512*4vnniw use NO dash between
+        # 'avx512' and the sub-feature (correct: -mno-avx5124fmaps). The
+        # -mno-avx512-4fmaps form (with a dash) is rejected by GCC and
+        # makes the whole build fail with "unrecognized command-line option".
         if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID STREQUAL "GNU")
             add_compile_options(
                 -mno-avx512f -mno-avx512pf -mno-avx512er -mno-avx512cd
                 -mno-avx512vl -mno-avx512bw -mno-avx512dq -mno-avx512ifma
                 -mno-avx512vbmi -mno-avx512vbmi2 -mno-avx512vnni
-                -mno-avx512bitalg -mno-avx512vpopcntdq -mno-avx512-4fmaps
-                -mno-avx512-4vnniw -mno-avx512vp2intersect
+                -mno-avx512bitalg -mno-avx512vpopcntdq
+                -mno-avx5124fmaps -mno-avx5124vnniw -mno-avx512vp2intersect
             )
         endif()
     endif()
diff --git a/references/avx-512-sigill-build-fix.md b/references/avx-512-sigill-build-fix.md
index f01a6ba..b1722d3 100644
--- a/references/avx-512-sigill-build-fix.md
+++ b/references/avx-512-sigill-build-fix.md
@@ -101,13 +101,17 @@ if(CMAKE_X86_64_BASELINE)
     # the whole AVX-512 family so a CI runner's EPYC 7763 (or any
     # AVX-512-capable build host) cannot leak AVX-512 into a binary
     # that needs to run on KVM EPYC, Ryzen 3000, or ARM64.
+    # NB: -mno-avx512*4fmaps / -mno-avx512*4vnniw use NO dash between
+    # 'avx512' and the sub-feature (correct: -mno-avx5124fmaps). The
+    # -mno-avx512-4fmaps form (with a dash) is rejected by GCC and
+    # makes the whole build fail with "unrecognized command-line option".
     if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID STREQUAL "GNU")
         add_compile_options(
             -mno-avx512f -mno-avx512pf -mno-avx512er -mno-avx512cd
             -mno-avx512vl -mno-avx512bw -mno-avx512dq -mno-avx512ifma
             -mno-avx512vbmi -mno-avx512vbmi2 -mno-avx512vnni
-            -mno-avx512bitalg -mno-avx512vpopcntdq -mno-avx512-4fmaps
-            -mno-avx512-4vnniw -mno-avx512vp2intersect
+            -mno-avx512bitalg -mno-avx512vpopcntdq
+            -mno-avx5124fmaps -mno-avx5124vnniw -mno-avx512vp2intersect
         )
     endif()
 endif()