diff --git a/share/config.fish b/share/config.fish
index cecdeceb0..388cc018d 100644
--- a/share/config.fish
+++ b/share/config.fish
@@ -8,6 +8,16 @@ set -g IFS \n\ \t
 set -qg __fish_added_user_paths
 or set -g __fish_added_user_paths
 
+# For one-off upgrades of the fish version, see __fish_config_interactive.fish
+if not set -q __fish_initialized
+    set -U __fish_initialized 0
+    if set -q __fish_init_2_39_8
+        set __fish_initialized 2398
+    else if set -q __fish_init_2_3_0
+        set __fish_initialized 2300
+    end
+end
+
 #
 # Create the default command_not_found handler
 #
@@ -154,7 +164,7 @@ end
 # Upgrade pre-existing abbreviations from the old "key=value" to the new "key value" syntax.
 # This needs to be in share/config.fish because __fish_config_interactive is called after sourcing
 # config.fish, which might contain abbr calls.
-if not set -q __fish_init_2_3_0
+if test $__fish_initialized -lt 2300
     if set -q fish_user_abbreviations
         set -l fab
         for abbr in $fish_user_abbreviations
@@ -162,7 +172,6 @@ if not set -q __fish_init_2_3_0
         end
         set fish_user_abbreviations $fab
     end
-    set -U __fish_init_2_3_0
 end
 
 #
diff --git a/share/functions/__fish_config_interactive.fish b/share/functions/__fish_config_interactive.fish
index 55a524b62..15adeac68 100644
--- a/share/functions/__fish_config_interactive.fish
+++ b/share/functions/__fish_config_interactive.fish
@@ -4,13 +4,11 @@
 # This function is called by the __fish_on_interactive function, which is defined in config.fish.
 #
 function __fish_config_interactive -d "Initializations that should be performed when entering interactive mode"
-    if not set -q __fish_init_3_x
+    if test $__fish_initialized -lt 3000
         # Perform transitions relevant to going from fish 2.x to 3.x.
 
         # Migrate old universal abbreviations to the new scheme.
         __fish_abbr_old | source
-
-        set -U __fish_init_3_x
     end
 
     # Make sure this function is only run once.
@@ -24,7 +22,7 @@ function __fish_config_interactive -d "Initializations that should be performed
     if not set -q fish_greeting
         set -l line1 (_ 'Welcome to fish, the friendly interactive shell')
         set -l line2 ''
-        if not set -q __fish_init_2_3_0
+        if test $__fish_initialized -lt 2300
             set line2 \n(_ 'Type `help` for instructions on how to use fish')
         end
         set -U fish_greeting "$line1$line2"
@@ -44,7 +42,7 @@ function __fish_config_interactive -d "Initializations that should be performed
 
     #
     # If we are starting up for the first time, set various defaults.
-    if not set -q __fish_init_3_1_0
+    if test $__fish_initialized -lt 3100
 
         # Regular syntax highlighting colors
         __init_uvar fish_color_normal normal
@@ -89,9 +87,6 @@ function __fish_config_interactive -d "Initializations that should be performed
         # Directory history colors
         #
         __init_uvar fish_color_history_current --bold
-
-        set -e __fish_init_2_39_8
-        set -U __fish_init_3_1_0
     end
 
     #
@@ -341,4 +336,8 @@ function __fish_config_interactive -d "Initializations that should be performed
             end
         end
     end
+
+    # Bump this whenever some code below needs to run once when upgrading to a new version.
+    # The universal variable __fish_initialized is initialized in share/config.fish.
+    set __fish_initialized 3100
 end