diff --git a/src/env.cpp b/src/env.cpp
index 07c8e3a41..52054e97a 100644
--- a/src/env.cpp
+++ b/src/env.cpp
@@ -625,8 +625,6 @@ static void react_to_variable_change(const wchar_t *op, const wcstring &key, env
     auto dispatch = var_dispatch_table.find(key);
     if (dispatch != var_dispatch_table.end()) {
         (*dispatch->second)(op, key, vars);
-    } else if (string_prefixes_string(L"_fish_abbr_", key)) {
-        update_abbr_cache(op, key);
     } else if (string_prefixes_string(L"fish_color_", key)) {
         reader_react_to_color_change();
     }
diff --git a/src/expand.cpp b/src/expand.cpp
index c9bba8fcd..d885dada3 100644
--- a/src/expand.cpp
+++ b/src/expand.cpp
@@ -1188,34 +1188,33 @@ bool fish_xdm_login_hack_hack_hack_hack(std::vector<std::string> *cmds, int argc
     return result;
 }
 
-static owning_lock<std::map<wcstring, wcstring>> s_abbreviations;
-void update_abbr_cache(const wchar_t *op, const wcstring &varname) {
-    wcstring abbr;
-    if (!unescape_string(varname.substr(wcslen(L"_fish_abbr_")), &abbr, 0, STRING_STYLE_VAR)) {
-        debug(1, L"Abbreviation var '%ls' is not correctly encoded, ignoring it.", varname.c_str());
-        return;
-    }
-    auto abbreviations = s_abbreviations.acquire();
-    abbreviations->erase(abbr);
-    if (wcscmp(op, L"ERASE") != 0) {
-        const auto expansion = env_get(varname);
-        if (!expansion.missing_or_empty()) {
-            abbreviations->emplace(abbr, expansion->as_string());
-        }
-    }
-}
+maybe_t<wcstring> expand_abbreviation(const wcstring &src) {
+    if (src.empty()) return none();
 
-bool expand_abbreviation(const wcstring &src, wcstring *output) {
-    if (src.empty()) return false;
-
-    auto abbreviations = s_abbreviations.acquire();
-    auto abbr = abbreviations->find(src);
-    if (abbr == abbreviations->end()) return false;
-    if (output != NULL) output->assign(abbr->second);
-    return true;
+    const auto &vars = env_stack_t::principal();
+    wcstring unesc_src;
+    if (!unescape_string(src, &unesc_src, STRING_STYLE_VAR)) {
+        return none();
+    }
+    wcstring var_name = L"_fish_abbr_" + unesc_src;
+    auto var_value = vars.get(var_name);
+    if (var_value) {
+        return var_value->as_string();
+    }
+    return none();
 }
 
 std::map<wcstring, wcstring> get_abbreviations() {
-    auto abbreviations = s_abbreviations.acquire();
-    return *abbreviations;
+    // TODO: try to make this cheaper
+    const auto &vars = env_stack_t::principal();
+    const size_t fish_abbr_len = wcslen(L"_fish_abbr_");
+    auto names = vars.get_names(0);
+    std::map<wcstring, wcstring> result;
+    for (const wcstring &name : names) {
+        if (string_prefixes_string(L"_fish_abbr_", name)) {
+            result[name.substr(fish_abbr_len)] = vars.get(name)->as_string();
+        }
+    }
+    return result;
 }
+
diff --git a/src/expand.h b/src/expand.h
index 95b3c151b..d64f64eed 100644
--- a/src/expand.h
+++ b/src/expand.h
@@ -14,6 +14,7 @@
 #include <vector>
 
 #include "common.h"
+#include "maybe.h"
 #include "parse_constants.h"
 
 class env_var_t;
@@ -156,10 +157,9 @@ void expand_tilde(wcstring &input);
 /// Perform the opposite of tilde expansion on the string, which is modified in place.
 wcstring replace_home_directory_with_tilde(const wcstring &str);
 
-/// Abbreviation support. Expand src as an abbreviation, returning true if one was found, false if
-/// not. If result is not-null, returns the abbreviation by reference.
-void update_abbr_cache(const wchar_t *op, const wcstring &varname);
-bool expand_abbreviation(const wcstring &src, wcstring *output);
+/// Abbreviation support. Expand src as an abbreviation, returning the expanded form if found,
+/// none() if not.
+maybe_t<wcstring> expand_abbreviation(const wcstring &src);
 
 /// \return a snapshot of all abbreviations as a map abbreviation->expansion.
 std::map<wcstring, wcstring> get_abbreviations();
diff --git a/src/fish_tests.cpp b/src/fish_tests.cpp
index 23283eadd..ce640296b 100644
--- a/src/fish_tests.cpp
+++ b/src/fish_tests.cpp
@@ -1781,19 +1781,19 @@ static void test_abbreviations() {
         if (ret != 0) err(L"Unable to set abbreviation variable");
     }
 
-    wcstring result;
-    if (expand_abbreviation(L"", &result)) err(L"Unexpected success with empty abbreviation");
-    if (expand_abbreviation(L"nothing", &result))
-        err(L"Unexpected success with missing abbreviation");
+    if (expand_abbreviation(L"")) err(L"Unexpected success with empty abbreviation");
+    if (expand_abbreviation(L"nothing")) err(L"Unexpected success with missing abbreviation");
 
-    if (!expand_abbreviation(L"gc", &result)) err(L"Unexpected failure with gc abbreviation");
-    if (result != L"git checkout") err(L"Wrong abbreviation result for gc");
-    result.clear();
+    auto mresult = expand_abbreviation(L"gc");
+    if (!mresult) err(L"Unexpected failure with gc abbreviation");
+    if (*mresult != L"git checkout") err(L"Wrong abbreviation result for gc");
 
-    if (!expand_abbreviation(L"foo", &result)) err(L"Unexpected failure with foo abbreviation");
-    if (result != L"bar") err(L"Wrong abbreviation result for foo");
+    mresult = expand_abbreviation(L"foo");
+    if (!mresult) err(L"Unexpected failure with foo abbreviation");
+    if (*mresult != L"bar") err(L"Wrong abbreviation result for foo");
 
     bool expanded;
+    wcstring result;
     expanded = reader_expand_abbreviation_in_command(L"just a command", 3, &result);
     if (expanded) err(L"Command wrongly expanded on line %ld", (long)__LINE__);
     expanded = reader_expand_abbreviation_in_command(L"gc somebranch", 0, &result);
diff --git a/src/highlight.cpp b/src/highlight.cpp
index 758660981..94a5ae52b 100644
--- a/src/highlight.cpp
+++ b/src/highlight.cpp
@@ -1015,7 +1015,7 @@ static bool command_is_valid(const wcstring &cmd, enum parse_statement_decoratio
     if (!is_valid && function_ok) is_valid = function_exists_no_autoload(cmd, vars);
 
     // Abbreviations
-    if (!is_valid && abbreviation_ok) is_valid = expand_abbreviation(cmd, NULL);
+    if (!is_valid && abbreviation_ok) is_valid = expand_abbreviation(cmd).has_value();
 
     // Regular commands
     if (!is_valid && command_ok) is_valid = path_get_path(cmd, NULL, vars);
diff --git a/src/reader.cpp b/src/reader.cpp
index 26c2cab80..e7737696a 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -747,14 +747,13 @@ bool reader_expand_abbreviation_in_command(const wcstring &cmdline, size_t curso
     bool result = false;
     if (matching_cmd_node) {
         const wcstring token = matching_cmd_node.get_source(subcmd);
-        wcstring abbreviation;
-        if (expand_abbreviation(token, &abbreviation)) {
+        if (auto abbreviation = expand_abbreviation(token)) {
             // There was an abbreviation! Replace the token in the full command. Maintain the
             // relative position of the cursor.
             if (output != NULL) {
                 output->assign(cmdline);
                 source_range_t r = *matching_cmd_node.source_range();
-                output->replace(subcmd_offset + r.start, r.length, abbreviation);
+                output->replace(subcmd_offset + r.start, r.length, *abbreviation);
             }
             result = true;
         }