diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5dccc86fd4..829a872dcd 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -326,7 +326,7 @@ jobs:
           if [ ${{ matrix.use_asan }} ]; then
             # Work around spurious crashes by running the test again.
             # See https://github.com/google/sanitizers/issues/1353
-            if fgrep -q 'LeakSanitizer has encountered a fatal error' test.out; then
+            if grep -qF 'LeakSanitizer has encountered a fatal error' test.out; then
                 echo '+++ Rerunning the tests once again after LeakSanitizer crash +++'
                 unset rc
                 ./test || rc=$?
@@ -376,7 +376,7 @@ jobs:
 
           /bin/bash -o pipefail -c "xvfb-run -a -s '-screen 0 1600x1200x24' ./test_gui -d 1 $wx_tests_selection 2>&1 | tee -a test_gui.out" || rc=$?
           if [ -n "$rc" ]; then
-            if fgrep -q '(core dumped)' test_gui.out; then
+            if grep -qF '(core dumped)' test_gui.out; then
                 echo '*** Test crashed, trying to get more information ***'
                 gdb --quiet --core=core -ex 'where' -ex 'thread apply all bt' -ex 'q' ./test_gui
             fi
diff --git a/Makefile.in b/Makefile.in
index 4dbe88165b..08eb0a6419 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -34645,7 +34645,7 @@ distdir: @GUIDIST@
 	@# in other dist targets.
 	find $(DISTDIR) \( -name "CVS" -o -name ".cvsignore" -o -name "*.dsp" -o -name "*.dsw" -o -name "*.hh*" -o \
 			\( -name "makefile.*" -a ! -name "makefile.gcc" -a ! -name "makefile.unx" \) \) \
-			-print | egrep -v '/samples/.*\.hh.$$' | xargs rm -rf
+			-print | grep -vE '/samples/.*\.hh.$$' | xargs rm -rf
 
 dist: distdir
 	@cd _dist_dir && tar ch $(DISTDIRNAME) | gzip -f9 > ../$(WXARCHIVE);
diff --git a/build/aclocal/bakefile.m4 b/build/aclocal/bakefile.m4
index 2c0dcd9464..240f037a0c 100644
--- a/build/aclocal/bakefile.m4
+++ b/build/aclocal/bakefile.m4
@@ -44,7 +44,7 @@ AC_DEFUN([AC_BAKEFILE_GNUMAKE],
     AC_CACHE_CHECK([if make is GNU make], bakefile_cv_prog_makeisgnu,
     [
         if ( ${SHELL-sh} -c "${MAKE-make} --version" 2> /dev/null |
-                egrep -s GNU > /dev/null); then
+                grep -sE GNU > /dev/null); then
             bakefile_cv_prog_makeisgnu="yes"
         else
             bakefile_cv_prog_makeisgnu="no"
diff --git a/build/bakefiles/make_dist.mk b/build/bakefiles/make_dist.mk
index ff2a865f35..8e0d698b32 100644
--- a/build/bakefiles/make_dist.mk
+++ b/build/bakefiles/make_dist.mk
@@ -748,7 +748,7 @@ distdir: @GUIDIST@
 	@# in other dist targets.
 	find $(DISTDIR) \( -name "CVS" -o -name ".cvsignore" -o -name "*.dsp" -o -name "*.dsw" -o -name "*.hh*" -o \
 			\( -name "makefile.*" -a ! -name "makefile.gcc" -a ! -name "makefile.unx" \) \) \
-			-print | egrep -v '/samples/.*\.hh.$$' | xargs rm -rf
+			-print | grep -vE '/samples/.*\.hh.$$' | xargs rm -rf
 
 dist: distdir
 	@cd _dist_dir && tar ch $(DISTDIRNAME) | gzip -f9 > ../$(WXARCHIVE);
diff --git a/build/cmake/config.cmake b/build/cmake/config.cmake
index 84a8d31b0c..cda29109ef 100644
--- a/build/cmake/config.cmake
+++ b/build/cmake/config.cmake
@@ -102,9 +102,6 @@ function(wx_write_config)
     set(libdir "\${exec_prefix}/lib")
     set(bindir "\${exec_prefix}/bin")
 
-    find_program(EGREP egrep)
-    mark_as_advanced(EGREP)
-
     if(wxBUILD_MONOLITHIC)
         set(MONOLITHIC 1)
     else()
diff --git a/configure b/configure
index ebf498978a..879c62bf5b 100755
--- a/configure
+++ b/configure
@@ -41612,7 +41612,7 @@ if ${bakefile_cv_prog_makeisgnu+:} false; then :
 else
 
         if ( ${SHELL-sh} -c "${MAKE-make} --version" 2> /dev/null |
-                egrep -s GNU > /dev/null); then
+                grep -sE GNU > /dev/null); then
             bakefile_cv_prog_makeisgnu="yes"
         else
             bakefile_cv_prog_makeisgnu="no"
diff --git a/misc/unictabl/mk_fallbacks.sh b/misc/unictabl/mk_fallbacks.sh
index a4814186d1..4eb43823fb 100755
--- a/misc/unictabl/mk_fallbacks.sh
+++ b/misc/unictabl/mk_fallbacks.sh
@@ -40,7 +40,7 @@ cat _tmp6 | sort +2 > _tmp4
 cat _tmp4 | while read i ; do
     code=`echo $i | cut -c1-6`
     fallb=`echo $i | cut -c8-29`
-    cat _tmp4 | fgrep "$fallb" | cut -c1-6 | (read i ; 
+    cat _tmp4 | grep -F "$fallb" | cut -c1-6 | (read i ;
         echo "$code	$i" >> _tmp5)
 done
 
@@ -54,7 +54,7 @@ cat _tmp6 | sort +2 > _tmp4
 cat _tmp4 | while read i ; do
     code=`echo $i | cut -c1-6`
     fallb=`echo $i | cut -c8-27`
-    cat _tmp4 | fgrep "$fallb" | cut -c1-6 | (read i ; 
+    cat _tmp4 | grep -F "$fallb" | cut -c1-6 | (read i ;
         echo "$code	$i" >> _tmp5)
 done