diff --git a/asdf.fish b/asdf.fish
index eb33f090..15736301 100644
--- a/asdf.fish
+++ b/asdf.fish
@@ -9,7 +9,7 @@ set -l asdf_user_shims (
 )
 
 # Add asdf to PATH
-set -l asdf_bin_dirs $ASDF_DIR/bin $asdf_user_shims 
+set -l asdf_bin_dirs $ASDF_DIR/bin $asdf_user_shims
 
 for x in $asdf_bin_dirs
   if test -d $x
@@ -24,4 +24,4 @@ for x in $asdf_bin_dirs
 end
 
 # Load the asdf wrapper function
-source $ASDF_DIR/lib/asdf.fish
+. $ASDF_DIR/lib/asdf.fish
diff --git a/bin/asdf b/bin/asdf
index a5020436..0693133d 100755
--- a/bin/asdf
+++ b/bin/asdf
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 # shellcheck source=lib/utils.bash
-source "$(dirname "$(dirname "$0")")/lib/utils.bash"
+. "$(dirname "$(dirname "$0")")/lib/utils.bash"
 
 find_cmd() {
   local cmd_dir="$1"
@@ -74,12 +74,12 @@ asdf_cmd() {
     exec "$ASDF_CMD_FILE" "${@:${args_offset}}"
   elif [ -f "$ASDF_CMD_FILE" ]; then
     set -- "${@:${args_offset}}"
-    source "$ASDF_CMD_FILE"
+    . "$ASDF_CMD_FILE"
   else
     local asdf_cmd_dir
     asdf_cmd_dir="$(asdf_dir)/lib/commands"
     printf "%s\\n" "Unknown command: \`asdf ${*}\`" >&2
-    source "$asdf_cmd_dir/command-help.bash" >&2
+    . "$asdf_cmd_dir/command-help.bash" >&2
     return 127
   fi
 }
diff --git a/bin/private/asdf-exec b/bin/private/asdf-exec
index d24830cc..eec8b74e 100755
--- a/bin/private/asdf-exec
+++ b/bin/private/asdf-exec
@@ -5,7 +5,7 @@ printf "asdf is self upgrading shims to new asdf exec ...\\n"
 
 asdf_dir="$(dirname "$(dirname "$(dirname "$0")")")"
 # shellcheck source=lib/utils.bash
-source "$asdf_dir/lib/utils.bash"
+. "$asdf_dir/lib/utils.bash"
 rm "$(asdf_data_dir)"/shims/*
 "$asdf_dir"/bin/asdf reshim
 shim_name=$(basename "$2")
diff --git a/lib/asdf.fish b/lib/asdf.fish
index 34a67886..698b5444 100644
--- a/lib/asdf.fish
+++ b/lib/asdf.fish
@@ -7,7 +7,7 @@ function asdf
     switch "$command"
         case "shell"
             # source commands that need to export variables
-            source (asdf export-shell-version fish $argv | psub)
+            . (asdf export-shell-version fish $argv | psub)
         case '*'
             # forward other commands to asdf script
             command asdf "$command" $argv
diff --git a/lib/commands/command-global.bash b/lib/commands/command-global.bash
index 0bfaa06f..89f52518 100644
--- a/lib/commands/command-global.bash
+++ b/lib/commands/command-global.bash
@@ -1,5 +1,5 @@
 # -*- sh -*-
 
 # shellcheck source=lib/commands/version_commands.bash
-source "$(dirname "$ASDF_CMD_FILE")/version_commands.bash"
+. "$(dirname "$ASDF_CMD_FILE")/version_commands.bash"
 version_command global "$@"
diff --git a/lib/commands/command-local.bash b/lib/commands/command-local.bash
index 50bf390b..78443d49 100644
--- a/lib/commands/command-local.bash
+++ b/lib/commands/command-local.bash
@@ -1,7 +1,7 @@
 # -*- sh -*-
 
 # shellcheck source=lib/commands/version_commands.bash
-source "$(dirname "$ASDF_CMD_FILE")/version_commands.bash"
+. "$(dirname "$ASDF_CMD_FILE")/version_commands.bash"
 
 local_command() {
   local parent=false
diff --git a/lib/commands/command-plugin-test.bash b/lib/commands/command-plugin-test.bash
index 32cff4a0..e95e63a7 100644
--- a/lib/commands/command-plugin-test.bash
+++ b/lib/commands/command-plugin-test.bash
@@ -55,7 +55,7 @@ plugin_test_command() {
     export ASDF_DATA_DIR=$TEST_DIR
 
     # shellcheck disable=SC1090
-    source "$ASDF_DIR/asdf.sh"
+    . "$ASDF_DIR/asdf.sh"
 
     if ! (asdf plugin-add "$plugin_name" "$plugin_url"); then
       fail_test "could not install $plugin_name from $plugin_url"
diff --git a/lib/commands/command-reshim.bash b/lib/commands/command-reshim.bash
index b54b68c9..92720e34 100644
--- a/lib/commands/command-reshim.bash
+++ b/lib/commands/command-reshim.bash
@@ -1,7 +1,7 @@
 # -*- sh -*-
 
 # shellcheck source=lib/commands/reshim.bash
-source "$(dirname "$ASDF_CMD_FILE")/reshim.bash"
+. "$(dirname "$ASDF_CMD_FILE")/reshim.bash"
 
 reshim_command() {
   local plugin_name=$1
diff --git a/lib/commands/command-uninstall.bash b/lib/commands/command-uninstall.bash
index a4553cd7..37ae44dd 100644
--- a/lib/commands/command-uninstall.bash
+++ b/lib/commands/command-uninstall.bash
@@ -1,7 +1,7 @@
 # -*- sh -*-
 
 # shellcheck source=lib/commands/reshim.bash
-source "$(dirname "$ASDF_CMD_FILE")/reshim.bash"
+. "$(dirname "$ASDF_CMD_FILE")/reshim.bash"
 
 uninstall_command() {
   local plugin_name=$1
diff --git a/lib/utils.bash b/lib/utils.bash
index 51d35888..58757d66 100644
--- a/lib/utils.bash
+++ b/lib/utils.bash
@@ -566,7 +566,7 @@ with_plugin_env() {
   ASDF_INSTALL_TYPE=$install_type \
     ASDF_INSTALL_VERSION=$version \
     ASDF_INSTALL_PATH=$install_path \
-    source "${plugin_path}/bin/exec-env"
+    . "${plugin_path}/bin/exec-env"
 
   PATH=$path "$callback"
 }
@@ -658,7 +658,7 @@ get_shim_versions() {
 
 preset_versions() {
   shim_name=$1
-  shim_plugin_versions "${shim_name}" | cut -d' ' -f 1 | uniq | xargs -IPLUGIN bash -c "source $(asdf_dir)/lib/utils.bash; printf \"%s %s\\n\" PLUGIN \$(get_preset_version_for PLUGIN)"
+  shim_plugin_versions "${shim_name}" | cut -d' ' -f 1 | uniq | xargs -IPLUGIN bash -c ". $(asdf_dir)/lib/utils.bash; printf \"%s %s\\n\" PLUGIN \$(get_preset_version_for PLUGIN)"
 }
 
 select_from_preset_version() {
diff --git a/test/asdf_fish.bats b/test/asdf_fish.bats
index 16f07492..745f52e7 100644
--- a/test/asdf_fish.bats
+++ b/test/asdf_fish.bats
@@ -17,7 +17,7 @@ cleaned_path() {
     set -e ASDF_DATA_DIR
     set PATH $(cleaned_path)
 
-    source asdf.fish
+    . asdf.fish
     echo \$ASDF_DIR
   ")
 
@@ -32,7 +32,7 @@ cleaned_path() {
    set -e ASDF_DATA_DIR
    set PATH $(cleaned_path)
 
-   source (pwd)/asdf.fish  # if the full path is not passed, status -f will return the relative path
+   . (pwd)/asdf.fish  # if the full path is not passed, status -f will return the relative path
    echo \$PATH
  ")
 
@@ -48,8 +48,8 @@ cleaned_path() {
     set -e ASDF_DATA_DIR
     set PATH $(cleaned_path)
 
-    source asdf.fish
-    source asdf.fish
+    . asdf.fish
+    . asdf.fish
     echo \$PATH
   ")
 
@@ -64,7 +64,7 @@ cleaned_path() {
     set -e ASDF_DIR
     set PATH $(cleaned_path)
 
-    source asdf.fish
+    . asdf.fish
     type asdf
   ")
 
diff --git a/test/version_commands.bats b/test/version_commands.bats
index f0cbb360..94b53770 100644
--- a/test/version_commands.bats
+++ b/test/version_commands.bats
@@ -231,14 +231,14 @@ teardown() {
 }
 
 @test "shell wrapper function should export ENV var" {
-  source $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
+  . $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
   asdf shell "dummy" "1.1.0"
   [ $(echo $ASDF_DUMMY_VERSION) = "1.1.0" ]
   unset ASDF_DUMMY_VERSION
 }
 
 @test "shell wrapper function with --unset should unset ENV var" {
-  source $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
+  . $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
   asdf shell "dummy" "1.1.0"
   [ $(echo $ASDF_DUMMY_VERSION) = "1.1.0" ]
   asdf shell "dummy" --unset
@@ -247,7 +247,7 @@ teardown() {
 }
 
 @test "shell wrapper function should return an error for missing plugins" {
-  source $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
+  . $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
   expected="No such plugin: nonexistent
 version 1.0.0 is not installed for nonexistent"
 
@@ -306,7 +306,7 @@ false"
 }
 
 @test "shell wrapper function should support latest" {
-  source $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
+  . $(dirname "$BATS_TEST_DIRNAME")/asdf.sh
   asdf shell "dummy" "latest"
   [ $(echo $ASDF_DUMMY_VERSION) = "2.0.0" ]
   unset ASDF_DUMMY_VERSION