diff --git a/src/services/organizeImports.ts b/src/services/organizeImports.ts
index 9c504357102..c2a7ea180bb 100644
--- a/src/services/organizeImports.ts
+++ b/src/services/organizeImports.ts
@@ -28,12 +28,12 @@ namespace ts.OrganizeImports {
         organizeImportsWorker(topLevelExportDecls, coalesceExports);
 
         for (const ambientModule of sourceFile.statements.filter(isAmbientModule)) {
-            const ambientModuleBody = getModuleBlock(ambientModule as ModuleDeclaration)!; // TODO: GH#18217
+            if (!ambientModule.body) { continue; }
 
-            const ambientModuleImportDecls = ambientModuleBody.statements.filter(isImportDeclaration);
+            const ambientModuleImportDecls = ambientModule.body.statements.filter(isImportDeclaration);
             organizeImportsWorker(ambientModuleImportDecls, coalesceAndOrganizeImports);
 
-            const ambientModuleExportDecls = ambientModuleBody.statements.filter(isExportDeclaration);
+            const ambientModuleExportDecls = ambientModule.body.statements.filter(isExportDeclaration);
             organizeImportsWorker(ambientModuleExportDecls, coalesceExports);
         }
 
@@ -81,11 +81,6 @@ namespace ts.OrganizeImports {
         }
     }
 
-    function getModuleBlock(moduleDecl: ModuleDeclaration): ModuleBlock | undefined {
-        const body = moduleDecl.body;
-        return body && !isIdentifier(body) ? (isModuleBlock(body) ? body : getModuleBlock(body)) : undefined;
-    }
-
     function removeUnusedImports(oldImports: ReadonlyArray<ImportDeclaration>, sourceFile: SourceFile, program: Program) {
         const typeChecker = program.getTypeChecker();
         const jsxNamespace = typeChecker.getJsxNamespace();
diff --git a/src/testRunner/unittests/services/organizeImports.ts b/src/testRunner/unittests/services/organizeImports.ts
index 1421780a4b4..d3fe55f9686 100644
--- a/src/testRunner/unittests/services/organizeImports.ts
+++ b/src/testRunner/unittests/services/organizeImports.ts
@@ -274,6 +274,16 @@ export const Other = 1;
                 assert.isEmpty(changes);
             });
 
+            it("doesn't crash on shorthand ambient module", () => {
+                const testFile = {
+                    path: "/a.ts",
+                    content: "declare module '*';",
+                };
+                const languageService = makeLanguageService(testFile);
+                const changes = languageService.organizeImports({ type: "file", fileName: testFile.path }, testFormatSettings, emptyOptions);
+                assert.isEmpty(changes);
+            });
+
             testOrganizeImports("Renamed_used",
                 {
                     path: "/test.ts",