diff --git a/agent-any/testsuite/tests/runtest.sh b/agent-any/testsuite/tests/runtest.sh
index f20df6e87..07213d06b 100755
--- a/agent-any/testsuite/tests/runtest.sh
+++ b/agent-any/testsuite/tests/runtest.sh
@@ -3,4 +3,4 @@
 unset Y2DEBUG
 unset Y2DEBUGGER
 
-(./runag_anyagent -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+(./runag_anyagent -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
diff --git a/agent-ini/testsuite/debug/runtest.sh b/agent-ini/testsuite/debug/runtest.sh
index d9a586afe..501ccde0e 100755
--- a/agent-ini/testsuite/debug/runtest.sh
+++ b/agent-ini/testsuite/debug/runtest.sh
@@ -10,7 +10,7 @@ cp $IN_FILE "$IN_FILE.test" 2> /dev/null
 (./runag_ini -l - $1 >$2) 2>&1 | grep -v "^$" \
     | grep -E '^....-..-.. ..:..:.. (.*\[agent-ini\]|<[1-5]>)' \
     | sed '-e s/^....-..-.. ..:..:.. [^)]*) //g' -e 's/:[0-9]\+ /:XXX /' > $3
-##(./runag_ini -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+##(./runag_ini -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
 
 cat "$IN_FILE.test" >> $2 2> /dev/null
 
diff --git a/agent-ini/testsuite/multi/runtest.sh b/agent-ini/testsuite/multi/runtest.sh
index 85cff441c..03635776e 100755
--- a/agent-ini/testsuite/multi/runtest.sh
+++ b/agent-ini/testsuite/multi/runtest.sh
@@ -15,7 +15,7 @@ done
 (./runag_ini -l - $1 >$2) 2>&1 | grep -v "^$" \
     | grep -E '^....-..-.. ..:..:.. (.*\[agent-ini\]|<[1-5]>)' \
     | sed '-e s/^....-..-.. ..:..:.. [^)]*) //g' -e 's/:[0-9]\+ /:XXX /' > $3
-##(./runag_ini -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+##(./runag_ini -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
 
 IN_FILE=${1%.*}".in.[0-9].test"
 for I in $IN_FILE; do
diff --git a/agent-ini/testsuite/tests/runtest.sh b/agent-ini/testsuite/tests/runtest.sh
index 89b6b8207..4eb137557 100755
--- a/agent-ini/testsuite/tests/runtest.sh
+++ b/agent-ini/testsuite/tests/runtest.sh
@@ -7,8 +7,8 @@ IN_FILE=${1%.*}".in"
 rm -f "$IN_FILE.test" 2> /dev/null
 cp $IN_FILE "$IN_FILE.test" 2> /dev/null
 
-(./runag_ini -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed '-e s/^....-..-.. ..:..:.. [^)]*) //g' -e 's/:[0-9]\+ /:XXX /' > $3
-##(./runag_ini -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+(./runag_ini -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed '-e s/^....-..-.. ..:..:.. [^)]*) //g' -e 's/:[0-9]\+ /:XXX /' > $3
+##(./runag_ini -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
 
 cat "$IN_FILE.test" >> $2 2> /dev/null
 
diff --git a/agent-modules/testsuite/tests/runtest.sh b/agent-modules/testsuite/tests/runtest.sh
index 1ffb1c1c4..e10ac1fbb 100755
--- a/agent-modules/testsuite/tests/runtest.sh
+++ b/agent-modules/testsuite/tests/runtest.sh
@@ -12,7 +12,7 @@ SCR_FILE=${1%.*}".scr"
 rm -f "$SCR_FILE" 2>/dev/null
 echo -e ".\n\n\`ag_modules(\n    \`ModulesConf(\"$IN_FILE.test\")\n)\n" >"$SCR_FILE"
 
-(./runmodules -l - "$1" >"$2") 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' >$3
+(./runmodules -l - "$1" >"$2") 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' >$3
 
 cat "$IN_FILE.test" >>"$2" 2>/dev/null
 exit 0
diff --git a/agent-process/testsuite/tests/runtest.sh b/agent-process/testsuite/tests/runtest.sh
index b9df45c54..3833caea7 100755
--- a/agent-process/testsuite/tests/runtest.sh
+++ b/agent-process/testsuite/tests/runtest.sh
@@ -9,7 +9,7 @@ export Y2DEBUGSHELL=1
 # ignore also milestones (they are not constant and logged by liby2util - cannot be simply turned off)
 # ignore also line numbers (any change in the core might make the testsuite fail)
 (./run_ag_process -l - $1 >$2) 2>&1 | \
-    fgrep -v -e " <0> " -e " <1> " | \
+    grep -F -v -e " <0> " -e " <1> " | \
     grep -v "^$" | \
     sed 's/^....-..-.. ..:..:.. [^)]*) //g' | \
     sed 's/^\(\[[^]]\+\] [^(]\+([^)]\+)\):[0-9]\+ \(.*\)/\1 \2/g' \
diff --git a/agent-resolver/testsuite/tests/runtest.sh b/agent-resolver/testsuite/tests/runtest.sh
index a4a5177d0..816c7b22b 100755
--- a/agent-resolver/testsuite/tests/runtest.sh
+++ b/agent-resolver/testsuite/tests/runtest.sh
@@ -12,7 +12,7 @@ SCR_FILE=${1%.*}".scr"
 rm -f "$SCR_FILE" 2>/dev/null
 echo -e ".\n\n\`ag_resolver(\n    \`ResolverAgent(\"$IN_FILE.test\")\n)\n" >"$SCR_FILE"
 
-(./runresolver -l - "$1" >"$2") 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' >$3
+(./runresolver -l - "$1" >"$2") 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' >$3
 
 cat "$IN_FILE.test" >>"$2" 2>/dev/null
 exit 0
diff --git a/agent-system/testsuite/tests/runtest.sh b/agent-system/testsuite/tests/runtest.sh
index 95d75fb95..2ebcd3ac1 100755
--- a/agent-system/testsuite/tests/runtest.sh
+++ b/agent-system/testsuite/tests/runtest.sh
@@ -6,4 +6,4 @@ unset Y2DEBUG
 unset Y2DEBUGGER
 export Y2DEBUGSHELL=1
 
-(./runag_system -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+(./runag_system -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
diff --git a/libycp/testsuite/mkdata.sh b/libycp/testsuite/mkdata.sh
index b03d74f00..738d29a9f 100755
--- a/libycp/testsuite/mkdata.sh
+++ b/libycp/testsuite/mkdata.sh
@@ -1,5 +1,5 @@
 #! /bin/bash
 # mkdata make test data
 #
-(../runycp <$1.ycp >$1.out) 2>&1 | fgrep -v " <0> " | sed 's/^....-..-.. ..:..:.. [^:]*://g' > $1.err
+(../runycp <$1.ycp >$1.out) 2>&1 | grep -F -v " <0> " | sed 's/^....-..-.. ..:..:.. [^:]*://g' > $1.err
 
diff --git a/libycp/testsuite/runtest.sh b/libycp/testsuite/runtest.sh
index c02d354ff..23afae115 100755
--- a/libycp/testsuite/runtest.sh
+++ b/libycp/testsuite/runtest.sh
@@ -9,5 +9,5 @@ export Y2SILENTSEARCH=1
 # for float::tolstring
 export LC_NUMERIC=cs_CZ.UTF8
 
-(./runycp -l - -I tests/Include -M tests/Module $1 >$2) 2>&1 | fgrep -v 'Electric Fence' | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+(./runycp -l - -I tests/Include -M tests/Module $1 >$2) 2>&1 | grep -F -v 'Electric Fence' | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
 exit 0
diff --git a/scr/testsuite/tests/runtest.sh b/scr/testsuite/tests/runtest.sh
index f38d72a0b..daa08d7cc 100755
--- a/scr/testsuite/tests/runtest.sh
+++ b/scr/testsuite/tests/runtest.sh
@@ -3,4 +3,4 @@
 unset Y2DEBUG
 unset Y2DEBUGGER
 
-(./runscr -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
+(./runscr -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed 's/^....-..-.. ..:..:.. [^)]*) //g' > $3
diff --git a/wfm/testsuite/tests/runtest.sh b/wfm/testsuite/tests/runtest.sh
index 76bd76d39..0adb75f9f 100755
--- a/wfm/testsuite/tests/runtest.sh
+++ b/wfm/testsuite/tests/runtest.sh
@@ -8,4 +8,4 @@ unset LANGUAGE
 unset Y2DEBUG
 unset Y2DEBUGGER
 
-(./runwfm -l - $1 >$2) 2>&1 | fgrep -v " <0> " | grep -v "^$" | sed -e 's/^....-..-.. ..:..:.. [^)]*) //g' -e 's/):[0-9]\+ /):XXX /' > $3
+(./runwfm -l - $1 >$2) 2>&1 | grep -F -v " <0> " | grep -v "^$" | sed -e 's/^....-..-.. ..:..:.. [^)]*) //g' -e 's/):[0-9]\+ /):XXX /' > $3