diff --git a/builds/cmake/CMakeLists.txt b/builds/cmake/CMakeLists.txt
index 5011bbff9f..ce2aadbbdf 100644
--- a/builds/cmake/CMakeLists.txt
+++ b/builds/cmake/CMakeLists.txt
@@ -166,9 +166,9 @@ set( enable-avx2 "no" CACHE BOOL "Compile with avx2 intrinsics (specifically -ma
 #------------------------------------------------------------------------------
 set( enable-avx512 "no" CACHE BOOL "Compile with avx512 intrinsics (specifically -mavx512bw -mavx512f)." )
 
-# Implement -Denable-sse4.
+# Implement -Denable-sse41.
 #------------------------------------------------------------------------------
-set( enable-sse4 "no" CACHE BOOL "Compile with sse4 intrinsics (specifically -msse4.1)." )
+set( enable-sse41 "no" CACHE BOOL "Compile with sse4.1 intrinsics (specifically -msse4.1)." )
 
 # Implement -Denable-shani.
 #------------------------------------------------------------------------------
@@ -280,10 +280,10 @@ if (enable-shani)
     endif()
 endif()
 
-if (enable-sse4)
-    check_cxx_compiler_flag("-msse4.1" HAS_FLAGS_SSE4)
+if (enable-sse41)
+    check_cxx_compiler_flag("-msse4.1" HAS_FLAGS_SSE41)
 
-    if (HAS_FLAGS_SSE4)
+    if (HAS_FLAGS_SSE41)
         add_compile_options( $<$<COMPILE_LANGUAGE:CXX>:-msse4.1> )
         set( CMAKE_REQUIRED_FLAGS_PREV "${CMAKE_REQUIRED_FLAGS}" )
         set( CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -msse4.1" )
@@ -296,17 +296,17 @@ if (enable-sse4)
             __m128i a = _mm_set1_epi32(0);
             __m128i b = _mm_set1_epi32(15);
             return _mm_extract_epi32(_mm_add_epi64(a, b), 2);
-        }" WITH_SSE4)
+        }" WITH_SSE41)
 
-    if (HAS_FLAGS_SSE4)
+    if (HAS_FLAGS_SSE41)
         set( CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS_PREV}" )
     endif()
 
-    if ( WITH_SSE4 )
-        add_compile_definitions( WITH_SSE4 )
-        set( sse4 "-DWITH_SSE4" )
+    if ( WITH_SSE41 )
+        add_compile_definitions( WITH_SSE41 )
+        set( sse41 "-DWITH_SSE41" )
     else()
-        message( FATAL_ERROR "Failed to enable WITH_SSE4" )
+        message( FATAL_ERROR "Failed to enable WITH_SSE41" )
     endif()
 endif()
 
diff --git a/configure.ac b/configure.ac
index f7051eae90..a18cb106d9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -141,15 +141,15 @@ AC_ARG_ENABLE([avx512],
     [enable_avx512=no])
 AC_MSG_RESULT([$enable_avx512])
 
-# Implement --enable-sse4.
+# Implement --enable-sse41.
 #------------------------------------------------------------------------------
-AC_MSG_CHECKING([--enable-sse4 option])
-AC_ARG_ENABLE([sse4],
-    AS_HELP_STRING([--enable-sse4],
-        [Compile with sse4 intrinsics (specifically -msse4.1). @<:@default=no@:>@]),
-    [enable_sse4=$enableval],
-    [enable_sse4=no])
-AC_MSG_RESULT([$enable_sse4])
+AC_MSG_CHECKING([--enable-sse41 option])
+AC_ARG_ENABLE([sse41],
+    AS_HELP_STRING([--enable-sse41],
+        [Compile with sse4.1 intrinsics (specifically -msse4.1). @<:@default=no@:>@]),
+    [enable_sse41=$enableval],
+    [enable_sse41=no])
+AC_MSG_RESULT([$enable_sse41])
 
 # Implement --enable-shani.
 #------------------------------------------------------------------------------
@@ -347,11 +347,11 @@ AS_IF([test x${enable_shani} != "xno"],
             return _mm_extract_epi32(_mm_sha256msg2_epu32(_mm_sha256msg1_epu32(_mm_sha256rnds2_epu32(a, b, k), b), a), 2);
           ]])])])
 
-AS_IF([test x${enable_sse4} != "xno"],
+AS_IF([test x${enable_sse41} != "xno"],
     [AX_CHECK_COMPILE_FLAG([-msse4.1],
-        [AC_DEFINE([WITH_SSE4])
+        [AC_DEFINE([WITH_SSE41])
          CXXFLAGS="$CXXFLAGS -msse4.1";
-         AC_SUBST([sse4], [-DWITH_SSE4])],
+         AC_SUBST([sse41], [-DWITH_SSE41])],
         [AC_MSG_ERROR([-msse4.1 not supported.])],
         [],
         [AC_LANG_PROGRAM(
diff --git a/libbitcoin-system.pc.in b/libbitcoin-system.pc.in
index 458f5a7baa..5a84353afa 100644
--- a/libbitcoin-system.pc.in
+++ b/libbitcoin-system.pc.in
@@ -29,7 +29,7 @@ Requires: @icu_i18n_PKG@ libsecp256k1 >= 0.1.0.20
 
 # Include directory and any other required compiler flags.
 #------------------------------------------------------------------------------
-Cflags: -I${includedir} @icu@ @avx2@ @avx512@ @shani@ @sse4@ @boost_CPPFLAGS@ @pthread_CPPFLAGS@
+Cflags: -I${includedir} @icu@ @avx2@ @avx512@ @shani@ @sse41@ @boost_CPPFLAGS@ @pthread_CPPFLAGS@
 
 # Lib directory, lib and any required that do not publish pkg-config.
 #------------------------------------------------------------------------------