diff --git a/projects/demo/src/app/app.component.ts b/projects/demo/src/app/app.component.ts
index bc42e95..4e9dc83 100644
--- a/projects/demo/src/app/app.component.ts
+++ b/projects/demo/src/app/app.component.ts
@@ -1,7 +1,6 @@
 import { DecimalPipe } from '@angular/common';
 import { Component } from '@angular/core';
-import { FaConfig, FaIconLibrary, FontAwesomeModule } from '@fortawesome/angular-fontawesome';
-import { IconDefinition, IconName } from '@fortawesome/fontawesome-svg-core';
+import { FaConfig, FaIconLibrary, FontAwesomeModule, IconDefinition } from '@fortawesome/angular-fontawesome';
 import { faFlag, faUser as regularUser } from '@fortawesome/free-regular-svg-icons';
 import {
   faAdjust,
@@ -48,7 +47,7 @@ export class AppComponent {
   faSpinner = faSpinner;
   faDummy: IconDefinition = {
     prefix: 'fad',
-    iconName: 'dummy' as IconName,
+    iconName: 'dummy',
     icon: [512, 512, [], 'f030', ['M50 50 H412 V250 H50 Z', 'M50 262 H412 V462 H50 Z']],
   };
 
diff --git a/src/lib/config.ts b/src/lib/config.ts
index 1bad0e3..9634ecd 100644
--- a/src/lib/config.ts
+++ b/src/lib/config.ts
@@ -1,5 +1,5 @@
 import { Injectable } from '@angular/core';
-import { IconDefinition, IconPrefix } from '@fortawesome/fontawesome-svg-core';
+import { IconDefinition, IconPrefix } from './types';
 
 @Injectable({ providedIn: 'root' })
 export class FaConfig {
diff --git a/src/lib/icon-library.ts b/src/lib/icon-library.ts
index d488c03..1b2515f 100644
--- a/src/lib/icon-library.ts
+++ b/src/lib/icon-library.ts
@@ -1,5 +1,5 @@
 import { Injectable } from '@angular/core';
-import { IconDefinition, IconName, IconPack, IconPrefix } from '@fortawesome/fontawesome-svg-core';
+import { IconDefinition, IconName, IconPack, IconPrefix } from './types';
 
 export interface FaIconLibraryInterface {
   addIcons(...icons: IconDefinition[]): void;
diff --git a/src/lib/icon/duotone-icon.component.ts b/src/lib/icon/duotone-icon.component.ts
index c0827aa..e927823 100644
--- a/src/lib/icon/duotone-icon.component.ts
+++ b/src/lib/icon/duotone-icon.component.ts
@@ -1,5 +1,6 @@
 import { Component, Input } from '@angular/core';
-import { IconDefinition, IconParams, IconProp } from '@fortawesome/fontawesome-svg-core';
+import { IconDefinition as CoreIconDefinition, IconParams } from '@fortawesome/fontawesome-svg-core';
+import { IconDefinition, IconProp } from '../types';
 import { FaIconComponent } from './icon.component';
 
 @Component({
@@ -49,7 +50,7 @@ export class FaDuotoneIconComponent extends FaIconComponent {
    */
   @Input() secondaryColor?: string;
 
-  protected findIconDefinition(i: IconProp | IconDefinition): IconDefinition | null {
+  protected findIconDefinition(i: IconProp | IconDefinition): CoreIconDefinition | null {
     const definition = super.findIconDefinition(i);
 
     if (definition != null && !Array.isArray(definition.icon[4])) {
diff --git a/src/lib/icon/icon.component.spec.ts b/src/lib/icon/icon.component.spec.ts
index ba70a79..de6f57d 100644
--- a/src/lib/icon/icon.component.spec.ts
+++ b/src/lib/icon/icon.component.spec.ts
@@ -1,6 +1,5 @@
 import { Component, ViewChild, ViewContainerRef } from '@angular/core';
 import { TestBed } from '@angular/core/testing';
-import { IconProp } from '@fortawesome/fontawesome-svg-core';
 import { faUser as faUserRegular } from '@fortawesome/free-regular-svg-icons';
 import { faCircle, faUser } from '@fortawesome/free-solid-svg-icons';
 import { Subject } from 'rxjs';
@@ -8,6 +7,7 @@ import { startWith } from 'rxjs/operators';
 import { initTest, queryByCss } from '../../testing/helpers';
 import { FaConfig } from '../config';
 import { FaIconLibrary } from '../icon-library';
+import { IconProp } from '../types';
 import { FaIconComponent } from './icon.component';
 
 describe('FaIconComponent', () => {
diff --git a/src/lib/icon/icon.component.ts b/src/lib/icon/icon.component.ts
index 88217e8..bf00db7 100644
--- a/src/lib/icon/icon.component.ts
+++ b/src/lib/icon/icon.component.ts
@@ -4,9 +4,8 @@ import {
   FaSymbol,
   FlipProp,
   icon,
-  IconDefinition,
+  IconDefinition as CoreIconDefinition,
   IconParams,
-  IconProp,
   parse,
   PullProp,
   RotateProp,
@@ -22,6 +21,7 @@ import { faClassList } from '../shared/utils/classlist.util';
 import { faNormalizeIconSpec } from '../shared/utils/normalize-icon-spec.util';
 import { FaStackItemSizeDirective } from '../stack/stack-item-size.directive';
 import { FaStackComponent } from '../stack/stack.component';
+import { IconDefinition, IconProp } from '../types';
 
 @Component({
   selector: 'fa-icon',
@@ -86,18 +86,18 @@ export class FaIconComponent implements OnChanges {
     }
   }
 
-  ngOnChanges(changes: SimpleChanges) {
+  ngOnChanges(changes: SimpleChanges): void {
     if (this.icon == null && this.config.fallbackIcon == null) {
       faWarnIfIconSpecMissing();
       return;
     }
 
     if (changes) {
-      const iconToBeRendered = this.icon != null ? this.icon : this.config.fallbackIcon;
-      const iconDefinition = this.findIconDefinition(iconToBeRendered);
+      const iconDefinition = this.findIconDefinition(this.icon ?? this.config.fallbackIcon);
       if (iconDefinition != null) {
         const params = this.buildParams();
-        this.renderIcon(iconDefinition, params);
+        const renderedIcon = icon(iconDefinition, params);
+        this.renderedIconHTML = this.sanitizer.bypassSecurityTrustHtml(renderedIcon.html.join('\n'));
       }
     }
   }
@@ -113,15 +113,15 @@ export class FaIconComponent implements OnChanges {
     this.ngOnChanges({});
   }
 
-  protected findIconDefinition(i: IconProp | IconDefinition): IconDefinition | null {
+  protected findIconDefinition(i: IconProp | IconDefinition): CoreIconDefinition | null {
     const lookup = faNormalizeIconSpec(i, this.config.defaultPrefix);
     if ('icon' in lookup) {
-      return lookup;
+      return lookup as CoreIconDefinition;
     }
 
     const definition = this.iconLibrary.getIconDefinition(lookup.prefix, lookup.iconName);
     if (definition != null) {
-      return definition;
+      return definition as CoreIconDefinition;
     }
 
     faWarnIfIconDefinitionMissing(lookup);
@@ -154,9 +154,4 @@ export class FaIconComponent implements OnChanges {
       },
     };
   }
-
-  private renderIcon(definition: IconDefinition, params: IconParams) {
-    const renderedIcon = icon(definition, params);
-    this.renderedIconHTML = this.sanitizer.bypassSecurityTrustHtml(renderedIcon.html.join('\n'));
-  }
 }
diff --git a/src/lib/public_api.ts b/src/lib/public_api.ts
index 3226f33..d9b69fb 100644
--- a/src/lib/public_api.ts
+++ b/src/lib/public_api.ts
@@ -9,3 +9,4 @@ export { FaLayersCounterComponent } from './layers/layers-counter.component';
 export { FaStackComponent } from './stack/stack.component';
 export { FaStackItemSizeDirective } from './stack/stack-item-size.directive';
 export { FaIconLibrary, FaIconLibraryInterface } from './icon-library';
+export { IconPrefix, IconName, IconLookup, IconDefinition, IconPack } from './types';
diff --git a/src/lib/shared/errors/warn-if-icon-html-missing.ts b/src/lib/shared/errors/warn-if-icon-html-missing.ts
index ce4149a..4062a5f 100644
--- a/src/lib/shared/errors/warn-if-icon-html-missing.ts
+++ b/src/lib/shared/errors/warn-if-icon-html-missing.ts
@@ -1,4 +1,4 @@
-import { IconLookup } from '@fortawesome/fontawesome-svg-core';
+import { IconLookup } from '../../types';
 
 export const faWarnIfIconDefinitionMissing = (iconSpec: IconLookup) => {
   throw new Error(
diff --git a/src/lib/shared/models/props.model.ts b/src/lib/shared/models/props.model.ts
index ad48af0..5d65e89 100644
--- a/src/lib/shared/models/props.model.ts
+++ b/src/lib/shared/models/props.model.ts
@@ -1,13 +1,13 @@
 import {
   FaSymbol,
   FlipProp,
-  IconProp,
   PullProp,
   RotateProp,
   SizeProp,
   Styles,
   Transform,
 } from '@fortawesome/fontawesome-svg-core';
+import { IconProp } from '../../types';
 
 /**
  * Fontawesome props.
diff --git a/src/lib/shared/utils/is-icon-lookup.util.ts b/src/lib/shared/utils/is-icon-lookup.util.ts
index 992b3bf..303f68c 100644
--- a/src/lib/shared/utils/is-icon-lookup.util.ts
+++ b/src/lib/shared/utils/is-icon-lookup.util.ts
@@ -1,4 +1,4 @@
-import { IconLookup, IconProp } from '@fortawesome/fontawesome-svg-core';
+import { IconLookup, IconProp } from '../../types';
 
 /**
  * Returns if is IconLookup or not.
diff --git a/src/lib/shared/utils/normalize-icon-spec.util.ts b/src/lib/shared/utils/normalize-icon-spec.util.ts
index e53eb07..1ea9ff7 100644
--- a/src/lib/shared/utils/normalize-icon-spec.util.ts
+++ b/src/lib/shared/utils/normalize-icon-spec.util.ts
@@ -1,4 +1,4 @@
-import { IconDefinition, IconLookup, IconPrefix, IconProp } from '@fortawesome/fontawesome-svg-core';
+import { IconDefinition, IconLookup, IconPrefix, IconProp } from '../../types';
 import { isIconLookup } from './is-icon-lookup.util';
 
 /**
@@ -12,9 +12,9 @@ export const faNormalizeIconSpec = (
     return iconSpec;
   }
 
-  if (typeof iconSpec === 'string') {
-    return { prefix: defaultPrefix, iconName: iconSpec };
+  if (Array.isArray(iconSpec) && iconSpec.length === 2) {
+    return { prefix: iconSpec[0], iconName: iconSpec[1] };
   }
 
-  return { prefix: iconSpec[0], iconName: iconSpec[1] };
+  return { prefix: defaultPrefix, iconName: iconSpec };
 };
diff --git a/src/lib/types.ts b/src/lib/types.ts
new file mode 100644
index 0000000..442e854
--- /dev/null
+++ b/src/lib/types.ts
@@ -0,0 +1,34 @@
+import { IconName as CoreIconName, IconPrefix as CoreIconPrefix } from '@fortawesome/fontawesome-svg-core';
+
+// Currently, when a union type of a primitive type is combined with literal
+// types, TypeScript loses all information about the combined literals. Thus,
+// when such type is used in an IDE with autocompletion, no suggestions are
+// made for the declared literals.
+// Below types use a workaround from [Microsoft/TypeScript#29729](https://github.com/Microsoft/TypeScript/issues/29729).
+
+export type IconPrefix = CoreIconPrefix | (string & {});
+
+export type IconName = CoreIconName | (string & {});
+
+export interface IconLookup {
+  prefix: IconPrefix;
+  iconName: IconName;
+}
+
+export interface IconDefinition {
+  prefix: IconPrefix;
+  iconName: IconName;
+  icon: [
+    number, // width
+    number, // height
+    string[], // ligatures
+    string, // unicode
+    string | string[], // svgPathData
+  ];
+}
+
+export interface IconPack {
+  [key: string]: IconDefinition;
+}
+
+export type IconProp = IconName | [IconPrefix, IconName] | IconLookup;
diff --git a/src/testing/helpers.ts b/src/testing/helpers.ts
index 3940371..3c63f1e 100644
--- a/src/testing/helpers.ts
+++ b/src/testing/helpers.ts
@@ -1,7 +1,6 @@
 import { CommonModule } from '@angular/common';
 import { Type } from '@angular/core';
 import { ComponentFixture, TestBed } from '@angular/core/testing';
-import { IconDefinition, IconName } from '@fortawesome/fontawesome-svg-core';
 import { FaDuotoneIconComponent } from '../lib/icon/duotone-icon.component';
 import { FaIconComponent } from '../lib/icon/icon.component';
 import { FaLayersCounterComponent } from '../lib/layers/layers-counter.component';
@@ -9,6 +8,7 @@ import { FaLayersTextComponent } from '../lib/layers/layers-text.component';
 import { FaLayersComponent } from '../lib/layers/layers.component';
 import { FaStackItemSizeDirective } from '../lib/stack/stack-item-size.directive';
 import { FaStackComponent } from '../lib/stack/stack.component';
+import { IconDefinition } from '../lib/types';
 
 export const initTest = <T>(component: Type<T>, providers?: any[]): ComponentFixture<T> => {
   TestBed.configureTestingModule({
@@ -33,6 +33,6 @@ export const queryByCss = (fixture: ComponentFixture<any>, cssSelector: string):
 
 export const faDummy: IconDefinition = {
   prefix: 'fad',
-  iconName: 'dummy' as IconName,
+  iconName: 'dummy',
   icon: [512, 512, [], 'f030', ['M50 50 H412 V250 H50 Z', 'M50 262 H412 V462 H50 Z']],
 };
diff --git a/testing/src/icon/mock-icon-library.service.ts b/testing/src/icon/mock-icon-library.service.ts
index 6b079f0..7686951 100644
--- a/testing/src/icon/mock-icon-library.service.ts
+++ b/testing/src/icon/mock-icon-library.service.ts
@@ -1,10 +1,9 @@
 import { Injectable } from '@angular/core';
-import { FaIconLibraryInterface } from '@fortawesome/angular-fontawesome';
-import { IconDefinition, IconName, IconPrefix } from '@fortawesome/fontawesome-svg-core';
+import { FaIconLibraryInterface, IconDefinition, IconName, IconPrefix } from '@fortawesome/angular-fontawesome';
 
 export const dummyIcon: IconDefinition = {
   prefix: 'fad',
-  iconName: 'dummy' as IconName,
+  iconName: 'dummy',
   icon: [512, 512, [], 'f030', 'M50 50 H462 V462 H50 Z'],
 };