diff --git a/libexec/pyenv-rehash b/libexec/pyenv-rehash
index 4e31994e..0ca0f276 100755
--- a/libexec/pyenv-rehash
+++ b/libexec/pyenv-rehash
@@ -123,34 +123,62 @@ make_shims() {
   done
 }
 
-registered_shims=" "
+if ((${BASH_VERSINFO[0]} > 3)); then
 
-# Registers the name of a shim to be generated.
-register_shim() {
-  registered_shims="${registered_shims}${1} "
-}
+  declare -A registered_shims
 
-# Install all the shims registered via `make_shims` or `register_shim` directly.
-install_registered_shims() {
-  local shim file
-  for shim in $registered_shims; do
-    file="${SHIM_PATH}/${shim}"
-    [ -e "$file" ] || cp "$PROTOTYPE_SHIM_PATH" "$file"
-  done
-}
+  # Registers the name of a shim to be generated.
+  register_shim() {
+    registered_shims["$1"]=1
+  }
 
-# Once the registered shims have been installed, we make a second pass
-# over the contents of the shims directory. Any file that is present
-# in the directory but has not been registered as a shim should be
-# removed.
-remove_stale_shims() {
-  local shim
-  for shim in "$SHIM_PATH"/*; do
-    if [[ "$registered_shims" != *" ${shim##*/} "* ]]; then
-      rm -f "$shim"
-    fi
-  done
-}
+  # Install all shims registered via `make_shims` or `register_shim` directly.
+  install_registered_shims() {
+    local shim file
+    for shim in "${!registered_shims[@]}"; do
+      file="${SHIM_PATH}/${shim}"
+      [ -e "$file" ] || cp "$PROTOTYPE_SHIM_PATH" "$file"
+    done
+  }
+
+  # Once the registered shims have been installed, we make a second pass
+  # over the contents of the shims directory. Any file that is present
+  # in the directory but has not been registered as a shim should be
+  # removed.
+  remove_stale_shims() {
+    local shim
+    for shim in "$SHIM_PATH"/*; do
+      if [[ ! ${registered_shims["${shim##*/}"]} ]]; then
+        rm -f "$shim"
+      fi
+    done
+  }
+
+else # Same for bash < 4.
+
+    registered_shims=" "
+
+    register_shim() {
+      registered_shims="${registered_shims}${1} "
+    }
+
+    install_registered_shims() {
+      local shim file
+      for shim in $registered_shims; do
+        file="${SHIM_PATH}/${shim}"
+        [ -e "$file" ] || cp "$PROTOTYPE_SHIM_PATH" "$file"
+      done
+    }
+
+    remove_stale_shims() {
+      local shim
+      for shim in "$SHIM_PATH"/*; do
+        if [[ "$registered_shims" != *" ${shim##*/} "* ]]; then
+          rm -f "$shim"
+        fi
+      done
+    }
+fi
 
 shopt -s nullglob
 
diff --git a/libexec/pyenv-versions b/libexec/pyenv-versions
index 019c0e90..91c99512 100755
--- a/libexec/pyenv-versions
+++ b/libexec/pyenv-versions
@@ -64,16 +64,27 @@ if [ -d "$versions_dir" ]; then
   versions_dir="$(realpath "$versions_dir")"
 fi
 
+if ((${BASH_VERSINFO[0]} > 3)); then
+  declare -A current_versions
+else
+  current_versions=()
+fi
 if [ -n "$bare" ]; then
   hit_prefix=""
   miss_prefix=""
-  current_versions=()
   include_system=""
 else
   hit_prefix="* "
   miss_prefix="  "
   OLDIFS="$IFS"
-  IFS=: current_versions=($(pyenv-version-name || true))
+  IFS=:
+  if ((${BASH_VERSINFO[0]} > 3)); then
+    for i in $(pyenv-version-name || true); do
+      current_versions["$i"]="1"
+    done
+  else
+    current_versions=($(pyenv-version-name || true))
+  fi
   IFS="$OLDIFS"
   include_system="1"
 fi
@@ -93,7 +104,9 @@ exists() {
 }
 
 print_version() {
-  if exists "$1" "${current_versions[@]}"; then
+  if [[ ${BASH_VERSINFO[0]} -ge 4 && ${current_versions["$1"]} ]]; then
+    echo "${hit_prefix}$1 (set by $(pyenv-version-origin))"
+  elif (( ${BASH_VERSINFO[0]} < 3 )) && exists "$1" "${current_versions[@]}"; then
     echo "${hit_prefix}$1 (set by $(pyenv-version-origin))"
   else
     echo "${miss_prefix}$1"