diff --git a/packages/babylon/src/plugins/typescript.js b/packages/babylon/src/plugins/typescript.js
index c3b4735341..73b185ecb5 100644
--- a/packages/babylon/src/plugins/typescript.js
+++ b/packages/babylon/src/plugins/typescript.js
@@ -1280,7 +1280,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       noCalls: ?boolean,
       state: { stop: boolean },
     ): N.Expression {
-      if (this.eat(tt.bang)) {
+      if (!this.hasPrecedingLineBreak() && this.eat(tt.bang)) {
         const nonNullExpression: N.TsNonNullExpression = this.startNodeAt(
           startPos,
           startLoc,
diff --git a/packages/babylon/test/fixtures/typescript/cast/null-assertion-false-positive/actual.js b/packages/babylon/test/fixtures/typescript/cast/null-assertion-false-positive/actual.js
new file mode 100644
index 0000000000..0fce68865a
--- /dev/null
+++ b/packages/babylon/test/fixtures/typescript/cast/null-assertion-false-positive/actual.js
@@ -0,0 +1,2 @@
+a
+!b
diff --git a/packages/babylon/test/fixtures/typescript/cast/null-assertion-false-positive/expected.json b/packages/babylon/test/fixtures/typescript/cast/null-assertion-false-positive/expected.json
new file mode 100644
index 0000000000..042ce23ffc
--- /dev/null
+++ b/packages/babylon/test/fixtures/typescript/cast/null-assertion-false-positive/expected.json
@@ -0,0 +1,118 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 4,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 2,
+      "column": 2
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 4,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 2,
+        "column": 2
+      }
+    },
+    "sourceType": "module",
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 1,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 1
+          }
+        },
+        "expression": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 1,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 1
+            },
+            "identifierName": "a"
+          },
+          "name": "a"
+        }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 2,
+        "end": 4,
+        "loc": {
+          "start": {
+            "line": 2,
+            "column": 0
+          },
+          "end": {
+            "line": 2,
+            "column": 2
+          }
+        },
+        "expression": {
+          "type": "UnaryExpression",
+          "start": 2,
+          "end": 4,
+          "loc": {
+            "start": {
+              "line": 2,
+              "column": 0
+            },
+            "end": {
+              "line": 2,
+              "column": 2
+            }
+          },
+          "operator": "!",
+          "prefix": true,
+          "argument": {
+            "type": "Identifier",
+            "start": 3,
+            "end": 4,
+            "loc": {
+              "start": {
+                "line": 2,
+                "column": 1
+              },
+              "end": {
+                "line": 2,
+                "column": 2
+              },
+              "identifierName": "b"
+            },
+            "name": "b"
+          },
+          "extra": {
+            "parenthesizedArgument": false
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
\ No newline at end of file