diff --git a/CHANGELOG.md b/CHANGELOG.md
index b8d5f89..0400f31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,10 @@
 - `check`: removed subcommands of `check` command, unifying both into the parent command
 - `repo`: reorganized commands that change repo config: renamed/created `config auth`, `config description`, and `config headers` commands
 
+### Fixed
+
+- return "application/tm+json" as MIME type when fetching TMs via API
+
 ## [v0.1.1]
 
 ### Added
diff --git a/api/tm-catalog.openapi.yaml b/api/tm-catalog.openapi.yaml
index 5da534f..48addb4 100644
--- a/api/tm-catalog.openapi.yaml
+++ b/api/tm-catalog.openapi.yaml
@@ -268,7 +268,7 @@ paths:
 
             **For the schema of the returned Thing Model see** [Thing Model JSON schema](https://github.com/w3c/wot-thing-description/blob/main/validation/tm-json-schema-validation.json)
           content:
-            application/json:
+            application/tm+json:
               schema:
                 type: object
         '400':
@@ -355,7 +355,7 @@ paths:
 
             **For the schema of the returned Thing Model see** [Thing Model JSON schema](https://github.com/w3c/wot-thing-description/blob/main/validation/tm-json-schema-validation.json)
           content:
-            application/json:
+            application/tm+json:
               schema:
                 type: object
         '400':
diff --git a/internal/app/http/common.go b/internal/app/http/common.go
index c71f4c5..8c27eed 100644
--- a/internal/app/http/common.go
+++ b/internal/app/http/common.go
@@ -35,6 +35,7 @@ const (
 	HeaderXContentTypeOptions = "X-Content-Type-Options"
 	MimeText                  = "text/plain"
 	MimeJSON                  = "application/json"
+	MimeTMJSON                = "application/tm+json"
 	MimeOctetStream           = "application/octet-stream"
 	MimeProblemJSON           = "application/problem+json"
 	NoSniff                   = "nosniff"
diff --git a/internal/app/http/handler.go b/internal/app/http/handler.go
index 34b48df..5b15008 100644
--- a/internal/app/http/handler.go
+++ b/internal/app/http/handler.go
@@ -93,7 +93,7 @@ func (h *TmcHandler) GetThingModelByFetchName(w http.ResponseWriter, r *http.Req
 		return
 	}
 
-	HandleByteResponse(w, r, http.StatusOK, MimeJSON, data)
+	HandleByteResponse(w, r, http.StatusOK, MimeTMJSON, data)
 }
 
 // GetInventoryByID returns the metadata of a single TM by ID
@@ -127,7 +127,7 @@ func (h *TmcHandler) GetThingModelById(w http.ResponseWriter, r *http.Request, i
 		return
 	}
 
-	HandleByteResponse(w, r, http.StatusOK, MimeJSON, data)
+	HandleByteResponse(w, r, http.StatusOK, MimeTMJSON, data)
 }
 
 // DeleteThingModelById Delete a Thing Model by ID
diff --git a/internal/app/http/handler_test.go b/internal/app/http/handler_test.go
index 036f404..0b8cae2 100644
--- a/internal/app/http/handler_test.go
+++ b/internal/app/http/handler_test.go
@@ -646,7 +646,7 @@ func Test_FetchThingModel(t *testing.T) {
 		// when: calling the route
 		rec := testutils.NewRequest(http.MethodGet, route).RunOnHandler(httpHandler)
 		// then: it returns status 200
-		assertResponse200(t, rec)
+		assertResponseTM200(t, rec)
 		assert.Equal(t, tmContent, rec.Body.Bytes())
 	})
 
@@ -655,7 +655,7 @@ func Test_FetchThingModel(t *testing.T) {
 		// when: calling the route
 		rec := testutils.NewRequest(http.MethodGet, route+"?restoreId=false").RunOnHandler(httpHandler)
 		// then: it returns status 200
-		assertResponse200(t, rec)
+		assertResponseTM200(t, rec)
 		assert.Equal(t, tmContent, rec.Body.Bytes())
 	})
 	t.Run("with true restoreId", func(t *testing.T) {
@@ -663,7 +663,7 @@ func Test_FetchThingModel(t *testing.T) {
 		// when: calling the route
 		rec := testutils.NewRequest(http.MethodGet, route+"?restoreId=true").RunOnHandler(httpHandler)
 		// then: it returns status 200
-		assertResponse200(t, rec)
+		assertResponseTM200(t, rec)
 		assert.Equal(t, tmContent, rec.Body.Bytes())
 	})
 	t.Run("with invalid restoreId", func(t *testing.T) {
@@ -1266,6 +1266,11 @@ func assertResponse200(t *testing.T, rec *httptest.ResponseRecorder) {
 	assert.Equal(t, MimeJSON, rec.Header().Get(HeaderContentType))
 }
 
+func assertResponseTM200(t *testing.T, rec *httptest.ResponseRecorder) {
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, MimeTMJSON, rec.Header().Get(HeaderContentType))
+}
+
 func assertResponse201(t *testing.T, rec *httptest.ResponseRecorder) {
 	assert.Equal(t, http.StatusCreated, rec.Code)
 	assert.Equal(t, MimeJSON, rec.Header().Get(HeaderContentType))