diff --git a/packages/babel-parser/src/parser/location.js b/packages/babel-parser/src/parser/location.js
index 2b2675daebe3..89f619922c59 100644
--- a/packages/babel-parser/src/parser/location.js
+++ b/packages/babel-parser/src/parser/location.js
@@ -135,7 +135,7 @@ export const Errors = Object.freeze({
   StrictEvalArgumentsBinding: "Binding '%0' in strict mode",
   StrictFunction:
     "In strict mode code, functions can only be declared at top level or inside a block",
-  StrictOctalLiteral: "Octal literal in strict mode",
+  StrictOctalLiteral: "Legacy octal literals are not allowed in strict mode",
   StrictWith: "'with' in strict mode",
   SuperNotAllowed:
     "super() is only valid inside a class constructor of a subclass. Maybe a typo in the method name ('constructor') or not extending another class?",
diff --git a/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive-function/output.json b/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive-function/output.json
index a0c9784b85a3..2aa1a971decd 100644
--- a/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive-function/output.json
+++ b/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive-function/output.json
@@ -13,15 +13,15 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (2:4)",
-    "SyntaxError: Octal literal in strict mode (7:4)",
-    "SyntaxError: Octal literal in strict mode (8:4)",
-    "SyntaxError: Octal literal in strict mode (14:4)",
-    "SyntaxError: Octal literal in strict mode (19:4)",
-    "SyntaxError: Octal literal in strict mode (20:4)",
-    "SyntaxError: Octal literal in strict mode (25:2)",
-    "SyntaxError: Octal literal in strict mode (30:2)",
-    "SyntaxError: Octal literal in strict mode (31:2)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (2:4)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (7:4)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (8:4)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (14:4)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (19:4)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (20:4)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (25:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (30:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (31:2)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive/output.json b/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive/output.json
index a82b9fedbfd2..136553fe54ec 100644
--- a/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive/output.json
+++ b/packages/babel-parser/test/fixtures/core/regression/invalid-octal-strict-directive/output.json
@@ -13,18 +13,18 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (8:2)",
-    "SyntaxError: Octal literal in strict mode (9:2)",
-    "SyntaxError: Octal literal in strict mode (11:0)",
-    "SyntaxError: Octal literal in strict mode (12:0)",
-    "SyntaxError: Octal literal in strict mode (14:2)",
-    "SyntaxError: Octal literal in strict mode (14:10)",
-    "SyntaxError: Octal literal in strict mode (14:18)",
-    "SyntaxError: Octal literal in strict mode (1:2)",
-    "SyntaxError: Octal literal in strict mode (1:10)",
-    "SyntaxError: Octal literal in strict mode (1:18)",
-    "SyntaxError: Octal literal in strict mode (3:2)",
-    "SyntaxError: Octal literal in strict mode (4:2)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (8:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (9:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (11:0)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (12:0)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (14:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (14:10)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (14:18)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:10)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:18)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (3:2)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (4:2)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/regression/non-octal-float-strict-mode/output.json b/packages/babel-parser/test/fixtures/core/regression/non-octal-float-strict-mode/output.json
index bda31230047d..99253558c815 100644
--- a/packages/babel-parser/test/fixtures/core/regression/non-octal-float-strict-mode/output.json
+++ b/packages/babel-parser/test/fixtures/core/regression/non-octal-float-strict-mode/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:0)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:0)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/499/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/499/output.json
index 828fbbd75f29..4f1229be25b8 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/499/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/499/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:35)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:35)"
   ],
   "program": {
     "type": "Program",
@@ -158,4 +158,4 @@
     ],
     "directives": []
   }
-}
\ No newline at end of file
+}
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/500/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/500/output.json
index 80b638a4ba9d..343c7244d1d0 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/500/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/500/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:33)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:33)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/501/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/501/output.json
index f73cb42cd9cf..6d3d9feff343 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/501/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/501/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:38)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:38)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/502/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/502/output.json
index 9da2955cedd9..5eb3bcef0b18 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/502/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/502/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:36)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:36)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/503/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/503/output.json
index e52fa38ccf73..81ea6460e38d 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/503/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/503/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:69)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:69)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/522/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/522/output.json
index ebcddc617e04..98d2e052715b 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/522/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/522/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:65)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:65)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/550/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/550/output.json
index 592b89bb2700..9b383cded8fd 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/550/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/550/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (2:10)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (2:10)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/core/uncategorised/552/output.json b/packages/babel-parser/test/fixtures/core/uncategorised/552/output.json
index 40360963683f..a7d3e10860a2 100644
--- a/packages/babel-parser/test/fixtures/core/uncategorised/552/output.json
+++ b/packages/babel-parser/test/fixtures/core/uncategorised/552/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (2:10)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (2:10)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/es2015/uncategorised/126/output.json b/packages/babel-parser/test/fixtures/es2015/uncategorised/126/output.json
index bc672902ac10..eec866273312 100644
--- a/packages/babel-parser/test/fixtures/es2015/uncategorised/126/output.json
+++ b/packages/babel-parser/test/fixtures/es2015/uncategorised/126/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Constructor can't have get/set accessor (1:14)"
+    "SyntaxError: Constructor may not be a get/set accessor (1:14)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/es2015/uncategorised/249/output.json b/packages/babel-parser/test/fixtures/es2015/uncategorised/249/output.json
index e9646670830e..18c0889f74b8 100644
--- a/packages/babel-parser/test/fixtures/es2015/uncategorised/249/output.json
+++ b/packages/babel-parser/test/fixtures/es2015/uncategorised/249/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:21)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:21)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0094/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0094/output.json
index e9646670830e..18c0889f74b8 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0094/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0094/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:21)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:21)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0216/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0216/output.json
index 48c8fda845ba..f2a0068be6f2 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0216/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0216/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:2)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:2)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0217/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0217/output.json
index 828fbbd75f29..4f1229be25b8 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0217/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0217/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:35)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:35)"
   ],
   "program": {
     "type": "Program",
@@ -158,4 +158,4 @@
     ],
     "directives": []
   }
-}
\ No newline at end of file
+}
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0218/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0218/output.json
index 80b638a4ba9d..343c7244d1d0 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0218/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0218/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:33)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:33)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0219/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0219/output.json
index f73cb42cd9cf..6d3d9feff343 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0219/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0219/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:38)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:38)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0220/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0220/output.json
index 9da2955cedd9..5eb3bcef0b18 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0220/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0220/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:36)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:36)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0221/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0221/output.json
index 374201e48c95..05630566bf8a 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0221/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0221/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:36)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:36)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0222/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0222/output.json
index 1c7a53167a1c..abebf79057a8 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0222/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0222/output.json
@@ -13,8 +13,8 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:36)",
-    "SyntaxError: Octal literal in strict mode (1:57)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:36)",
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:57)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0223/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0223/output.json
index e52fa38ccf73..81ea6460e38d 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0223/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0223/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Octal literal in strict mode (1:69)"
+    "SyntaxError: Legacy octal literals are not allowed in strict mode (1:69)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0272/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0272/output.json
index 9e2fb8c7565d..d384085408b7 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0272/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0272/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Constructor can't have get/set accessor (1:13)"
+    "SyntaxError: Constructor may not be a get/set accessor (1:13)"
   ],
   "program": {
     "type": "Program",
diff --git a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0273/output.json b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0273/output.json
index 19909ea397d5..f3dcc44291e9 100644
--- a/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0273/output.json
+++ b/packages/babel-parser/test/fixtures/esprima/invalid-syntax/migrated_0273/output.json
@@ -13,7 +13,7 @@
     }
   },
   "errors": [
-    "SyntaxError: Constructor can't have get/set accessor (1:13)"
+    "SyntaxError: Constructor may not be a get/set accessor (1:13)"
   ],
   "program": {
     "type": "Program",