diff --git a/simon128-simd.cpp b/simon128-simd.cpp
index a9777092..faa81dcb 100644
--- a/simon128-simd.cpp
+++ b/simon128-simd.cpp
@@ -15,7 +15,6 @@
 // Uncomment for benchmarking C++ against SSE or NEON.
 // Do so in both simon.cpp and simon-simd.cpp.
 // #undef CRYPTOPP_SSSE3_AVAILABLE
-// #undef CRYPTOPP_SSE41_AVAILABLE
 // #undef CRYPTOPP_ARM_NEON_AVAILABLE
 
 #if (CRYPTOPP_SSSE3_AVAILABLE)
@@ -23,10 +22,6 @@
 # include <tmmintrin.h>
 #endif
 
-#if (CRYPTOPP_SSE41_AVAILABLE)
-# include <smmintrin.h>
-#endif
-
 #if defined(__AVX512F__) && defined(__AVX512VL__)
 # define CRYPTOPP_AVX512_ROTATE 1
 # include <immintrin.h>
diff --git a/simon64-simd.cpp b/simon64-simd.cpp
index b8b6b85a..208d85dd 100644
--- a/simon64-simd.cpp
+++ b/simon64-simd.cpp
@@ -14,7 +14,6 @@
 
 // Uncomment for benchmarking C++ against SSE or NEON.
 // Do so in both simon.cpp and simon-simd.cpp.
-// #undef CRYPTOPP_SSSE3_AVAILABLE
 // #undef CRYPTOPP_SSE41_AVAILABLE
 // #undef CRYPTOPP_ARM_NEON_AVAILABLE
 
diff --git a/speck128-simd.cpp b/speck128-simd.cpp
index fe42038d..171640a1 100644
--- a/speck128-simd.cpp
+++ b/speck128-simd.cpp
@@ -15,7 +15,6 @@
 // Uncomment for benchmarking C++ against SSE or NEON.
 // Do so in both speck.cpp and speck-simd.cpp.
 // #undef CRYPTOPP_SSSE3_AVAILABLE
-// #undef CRYPTOPP_SSE41_AVAILABLE
 // #undef CRYPTOPP_ARM_NEON_AVAILABLE
 
 #if (CRYPTOPP_SSSE3_AVAILABLE)
@@ -23,10 +22,6 @@
 # include <tmmintrin.h>
 #endif
 
-#if (CRYPTOPP_SSE41_AVAILABLE)
-# include <smmintrin.h>
-#endif
-
 #if defined(__AVX512F__) && defined(__AVX512VL__)
 # define CRYPTOPP_AVX512_ROTATE 1
 # include <immintrin.h>
diff --git a/speck64-simd.cpp b/speck64-simd.cpp
index 73e7ee76..79a46bfb 100644
--- a/speck64-simd.cpp
+++ b/speck64-simd.cpp
@@ -14,7 +14,6 @@
 
 // Uncomment for benchmarking C++ against SSE or NEON.
 // Do so in both speck.cpp and speck-simd.cpp.
-// #undef CRYPTOPP_SSSE3_AVAILABLE
 // #undef CRYPTOPP_SSE41_AVAILABLE
 // #undef CRYPTOPP_ARM_NEON_AVAILABLE