diff --git a/bash_completion b/bash_completion
index 8ab042a019b..3e19284d4fc 100644
--- a/bash_completion
+++ b/bash_completion
@@ -1112,7 +1112,7 @@ _parse_help()
     (
         case $cmd in
             -) exec cat ;;
-            *) _comp_dequote "$cmd" && LC_ALL=C "$ret" ${2:---help} 2>&1 ;;
+            *) _comp_dequote "$cmd" && type -- "$ret" &>/dev/null && LC_ALL=C "$ret" ${2:---help} 2>&1 ;;
         esac
     ) |
         while read -r line; do
@@ -1149,7 +1149,7 @@ _parse_usage()
     (
         case $cmd in
             -) exec cat ;;
-            *) _comp_dequote "$cmd" && LC_ALL=C "$ret" ${2:---usage} 2>&1 ;;
+            *) _comp_dequote "$cmd" && type -- "$ret" &>/dev/null && LC_ALL=C "$ret" ${2:---usage} 2>&1 ;;
         esac
     ) |
         while read -r line; do
@@ -1822,7 +1822,7 @@ _bashcomp_try_faketty()
 {
     if type unbuffer &>/dev/null; then
         unbuffer -p "$@"
-    elif script --version 2>&1 | command grep -qF util-linux; then
+    elif type script &>/dev/null && script --version 2>&1 | command grep -qF util-linux; then
         # BSD and Solaris "script" do not seem to have required features
         script -qaefc "$*" /dev/null
     else
diff --git a/completions/gcc b/completions/gcc
index 41913b01164..6fabfeea529 100644
--- a/completions/gcc
+++ b/completions/gcc
@@ -58,25 +58,25 @@ _gcc()
     complete -F _gcc gcc{,-5,-6,-7,-8} g++{,-5,-6,-7,-8} g77 g95 \
         gccgo{,-5,-6,-7,-8} gcj gfortran{,-5,-6,-7,-8} gpc &&
     {
-        if cc --version 2>/dev/null | command grep -q GCC ||
+        if type cc &>/dev/null && cc --version 2>/dev/null | command grep -q GCC ||
             [[ $(_realcommand cc) == *gcc* ]]; then
             complete -F _gcc cc
         else
             complete -F _minimal cc
         fi
-        if c++ --version 2>/dev/null | command grep -q GCC ||
+        if type c++ &>/dev/null && c++ --version 2>/dev/null | command grep -q GCC ||
             [[ $(_realcommand c++) == *g++* ]]; then
             complete -F _gcc c++
         else
             complete -F _minimal c++
         fi
-        if f77 --version 2>/dev/null | command grep -q GCC ||
+        if type f77 &>/dev/null && f77 --version 2>/dev/null | command grep -q GCC ||
             [[ $(_realcommand f77) == *gfortran* ]]; then
             complete -F _gcc f77
         else
             complete -F _minimal f77
         fi
-        if f95 --version 2>/dev/null | command grep -q GCC ||
+        if type f95 &>/dev/null && f95 --version 2>/dev/null | command grep -q GCC ||
             [[ $(_realcommand f95) == *gfortran* ]]; then
             complete -F _gcc f95
         else