diff --git a/common/test/keyboards/baseline/k_0201___ralt_2.kmn b/common/test/keyboards/baseline/k_0201___ralt_2.kmn
index 6606a5d96d5..d22af03e742 100644
--- a/common/test/keyboards/baseline/k_0201___ralt_2.kmn
+++ b/common/test/keyboards/baseline/k_0201___ralt_2.kmn
@@ -1,8 +1,8 @@
 store(&VERSION) '9.0'
 store(&NAME) '0201 - ralt 2'
 c Description: Tests Right Alt processing with non-US kbds.
-c keys: [K_A][K_B][K_C][RALT K_A]
-c expected: abcd
+c keys: [K_A][K_B][K_C][RALT K_A][K_A][K_B][K_C][K_A]
+c expected: abcdabca
 
 store(&TARGETS) 'any'
 
diff --git a/common/test/keyboards/baseline/k_0202___alt.js b/common/test/keyboards/baseline/k_0202___alt.js
new file mode 100644
index 00000000000..c0643cfca44
--- /dev/null
+++ b/common/test/keyboards/baseline/k_0202___alt.js
@@ -0,0 +1,34 @@
+
+KeymanWeb.KR(new Keyboard_k_0202___alt());
+
+function Keyboard_k_0202___alt()
+{
+  
+  this._v=(typeof keyman!="undefined"&&typeof keyman.version=="string")?parseInt(keyman.version,10):9;
+  this.KI="Keyboard_k_0202___alt";
+  this.KN="0202 - alt";
+  this.KMINVER="9.0";
+  this.KV=null;
+  this.KDU=0;
+  this.KH='';
+  this.KM=0;
+  this.KBVER="1.0";
+  this.KMBM=0x0040;
+  this.KVS=[];
+  this.gs=function(t,e) {
+    return this.g_main_0(t,e);
+  };
+  this.gs=function(t,e) {
+    return this.g_main_0(t,e);
+  };
+  this.g_main_0=function(t,e) {
+    var k=KeymanWeb,r=0,m=0;
+    if(k.KKM(e, 0x4040, 0x41)) {
+      if(k.KCM(1,t,"c",1)){
+        r=m=1;   // Line 13
+        k.KO(1,t,"cd");
+      }
+    }
+    return r;
+  };
+}
diff --git a/common/test/keyboards/baseline/k_0202___alt.kmn b/common/test/keyboards/baseline/k_0202___alt.kmn
new file mode 100755
index 00000000000..3c5415f7293
--- /dev/null
+++ b/common/test/keyboards/baseline/k_0202___alt.kmn
@@ -0,0 +1,13 @@
+store(&VERSION) '9.0'
+store(&NAME) '0202 - alt'
+c Description: Tests Alt processing with non-US kbds.
+c keys: [K_A][K_B][K_C][RALT K_A][K_A][K_B][K_C][K_A]
+c expected: abcdabca
+
+store(&TARGETS) 'any'
+
+begin Unicode > use(main)
+
+group(main) using keys
+
+'c' + [Alt K_A] > "cd"
diff --git a/common/test/keyboards/baseline/k_0202___alt.kmx b/common/test/keyboards/baseline/k_0202___alt.kmx
new file mode 100644
index 00000000000..14a61fc01b4
Binary files /dev/null and b/common/test/keyboards/baseline/k_0202___alt.kmx differ
diff --git a/core/tests/unit/kmx/meson.build b/core/tests/unit/kmx/meson.build
index 8193fe50468..152c5656cbb 100644
--- a/core/tests/unit/kmx/meson.build
+++ b/core/tests/unit/kmx/meson.build
@@ -51,6 +51,7 @@ tests = [
   'k_0107___punctkeys',
   'k_0200___ralt',
   'k_0201___ralt_2',
+  'k_0202___alt',
   'k_0203___generic_ctrlalt',
   'k_0300___deadkeys',
   'k_0301___multiple_deadkeys',
diff --git a/developer/src/kmcmplib/tests/meson.build b/developer/src/kmcmplib/tests/meson.build
index 7d90e03cf0e..9745699ace4 100644
--- a/developer/src/kmcmplib/tests/meson.build
+++ b/developer/src/kmcmplib/tests/meson.build
@@ -45,6 +45,7 @@ tests = [
   'k_0107___punctkeys',
   'k_0200___ralt',
   'k_0201___ralt_2',
+  'k_0202___alt',
   'k_0203___generic_ctrlalt',
   'k_0300___deadkeys',
   'k_0301___multiple_deadkeys',
diff --git a/web/src/test/auto/e2e/baseline/baseline.tests.ts b/web/src/test/auto/e2e/baseline/baseline.tests.ts
index 16f52f67c72..0abd219e025 100644
--- a/web/src/test/auto/e2e/baseline/baseline.tests.ts
+++ b/web/src/test/auto/e2e/baseline/baseline.tests.ts
@@ -43,7 +43,8 @@ const testsToFix = {
     'k_0105___vkey_input__ctrl_alt_2_.kmn', // kmx only
     'k_0106___smp.kmn', // kmx only
     'k_0200___ralt.kmn', // kmx only
-    'k_0201___ralt_2.kmn', // kmx only
+    'k_0201___ralt_2.kmn',
+    'k_0202___alt.kmn',
     'k_0203___generic_ctrlalt.kmn',
     'k_0400___groups_and_virtual_keys.kmn', // kmx only
     'k_0501___options_with_preset.kmn',
@@ -64,6 +65,8 @@ const testsToFix = {
   '.js': [
     'k_0000___null_keyboard.kmn',
     'k_0104___vkey_input__ctrl_alt_.kmn',
+    'k_0201___ralt_2.kmn',  // #15358
+    'k_0202___alt.kmn',     // #15358
     'k_0203___generic_ctrlalt.kmn',
     'k_0501___options_with_preset.kmn',
     'k_0503___options_with_save_and_preset.kmn',