diff --git a/spring-web/src/main/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolver.java b/spring-web/src/main/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolver.java
index e418e61c038..72672f913eb 100644
--- a/spring-web/src/main/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolver.java
+++ b/spring-web/src/main/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolver.java
@@ -95,7 +95,7 @@ public class MappingMediaTypeFileExtensionResolver implements MediaTypeFileExten
 
 	@Override
 	public List<String> resolveFileExtensions(MediaType mediaType) {
-		List<String> fileExtensions = this.fileExtensions.get(mediaType);
+		List<String> fileExtensions = this.fileExtensions.get(mediaType.removeQualityValue());
 		return (fileExtensions != null ? fileExtensions : Collections.emptyList());
 	}
 
diff --git a/spring-web/src/test/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolverTests.java b/spring-web/src/test/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolverTests.java
index 5d954e9126e..9b57668e739 100644
--- a/spring-web/src/test/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolverTests.java
+++ b/spring-web/src/test/java/org/springframework/web/accept/MappingMediaTypeFileExtensionResolverTests.java
@@ -53,6 +53,14 @@ class MappingMediaTypeFileExtensionResolverTests {
 				.resolveFileExtensions(MediaType.TEXT_HTML)).isEmpty();
 	}
 
+	@Test
+	void resolveExtensionsWithQualityParameter() {
+		List<String> extensions = new MappingMediaTypeFileExtensionResolver(DEFAULT_MAPPINGS)
+				.resolveFileExtensions(MediaType.parseMediaType("application/json;q=0.9"));
+
+		assertThat(extensions).containsExactly("json");
+	}
+
 	@Test // SPR-13747
 	public void lookupMediaTypeCaseInsensitive() {
 		assertThat(new MappingMediaTypeFileExtensionResolver(DEFAULT_MAPPINGS).lookupMediaType("JSON"))