diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index b2e4e3b9377..aa9bbccffd9 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -64,7 +64,7 @@ namespace ts {
 
         const compilerOptions = host.getCompilerOptions();
         const languageVersion = getEmitScriptTarget(compilerOptions);
-        const modulekind = getEmitModuleKind(compilerOptions);
+        const moduleKind = getEmitModuleKind(compilerOptions);
         const allowSyntheticDefaultImports = getAllowSyntheticDefaultImports(compilerOptions);
         const strictNullChecks = getStrictOptionValue(compilerOptions, "strictNullChecks");
         const strictFunctionTypes = getStrictOptionValue(compilerOptions, "strictFunctionTypes");
@@ -1085,7 +1085,7 @@ namespace ts {
             const declarationFile = getSourceFileOfNode(declaration);
             const useFile = getSourceFileOfNode(usage);
             if (declarationFile !== useFile) {
-                if ((modulekind && (declarationFile.externalModuleIndicator || useFile.externalModuleIndicator)) ||
+                if ((moduleKind && (declarationFile.externalModuleIndicator || useFile.externalModuleIndicator)) ||
                     (!compilerOptions.outFile && !compilerOptions.out) ||
                     isInTypeQuery(usage) ||
                     declaration.flags & NodeFlags.Ambient) {
@@ -18723,7 +18723,7 @@ namespace ts {
         }
 
         function checkImportMetaProperty(node: MetaProperty) {
-            if (languageVersion < ScriptTarget.ESNext && modulekind < ModuleKind.ESNext) {
+            if (languageVersion < ScriptTarget.ESNext && moduleKind < ModuleKind.ESNext) {
                 error(node, Diagnostics.The_import_meta_meta_property_is_only_allowed_using_ESNext_for_the_target_and_module_compiler_options);
             }
             const file = getSourceFileOfNode(node);
@@ -22329,7 +22329,7 @@ namespace ts {
 
         function checkCollisionWithRequireExportsInGeneratedCode(node: Node, name: Identifier) {
             // No need to check for require or exports for ES6 modules and later
-            if (modulekind >= ModuleKind.ES2015 || compilerOptions.noEmit) {
+            if (moduleKind >= ModuleKind.ES2015 || compilerOptions.noEmit) {
                 return;
             }
 
@@ -24518,7 +24518,7 @@ namespace ts {
                     }
                 }
                 else {
-                    if (modulekind >= ModuleKind.ES2015 && !(node.flags & NodeFlags.Ambient)) {
+                    if (moduleKind >= ModuleKind.ES2015 && !(node.flags & NodeFlags.Ambient)) {
                         // Import equals declaration is deprecated in es6 or above
                         grammarErrorOnNode(node, Diagnostics.Import_assignment_cannot_be_used_when_targeting_ECMAScript_modules_Consider_using_import_Asterisk_as_ns_from_mod_import_a_from_mod_import_d_from_mod_or_another_module_format_instead);
                     }
@@ -24556,7 +24556,7 @@ namespace ts {
                         error(node.moduleSpecifier, Diagnostics.Module_0_uses_export_and_cannot_be_used_with_export_Asterisk, symbolToString(moduleSymbol));
                     }
 
-                    if (modulekind !== ModuleKind.System && modulekind !== ModuleKind.ES2015 && modulekind !== ModuleKind.ESNext) {
+                    if (moduleKind !== ModuleKind.System && moduleKind !== ModuleKind.ES2015 && moduleKind !== ModuleKind.ESNext) {
                         checkExternalEmitHelpers(node, ExternalEmitHelpers.ExportStar);
                     }
                 }
@@ -24629,11 +24629,11 @@ namespace ts {
             }
 
             if (node.isExportEquals && !(node.flags & NodeFlags.Ambient)) {
-                if (modulekind >= ModuleKind.ES2015) {
+                if (moduleKind >= ModuleKind.ES2015) {
                     // export assignment is not supported in es6 modules
                     grammarErrorOnNode(node, Diagnostics.Export_assignment_cannot_be_used_when_targeting_ECMAScript_modules_Consider_using_export_default_or_another_module_format_instead);
                 }
-                else if (modulekind === ModuleKind.System) {
+                else if (moduleKind === ModuleKind.System) {
                     // system modules does not support export assignment
                     grammarErrorOnNode(node, Diagnostics.Export_assignment_is_not_supported_when_module_flag_is_system);
                 }
@@ -27790,7 +27790,7 @@ namespace ts {
         }
 
         function checkGrammarImportCallExpression(node: ImportCall): boolean {
-            if (modulekind === ModuleKind.ES2015) {
+            if (moduleKind === ModuleKind.ES2015) {
                 return grammarErrorOnNode(node, Diagnostics.Dynamic_import_cannot_be_used_when_targeting_ECMAScript_2015_modules);
             }