diff --git a/modules/structs/pull.go b/modules/structs/pull.go
index 7cc58217a0f17..449a62f517e67 100644
--- a/modules/structs/pull.go
+++ b/modules/structs/pull.go
@@ -188,4 +188,6 @@ type ChangedFile struct {
 	ContentsURL string `json:"contents_url,omitempty"`
 	// The raw URL to download the file
 	RawURL string `json:"raw_url,omitempty"`
+	// The patch text for the file changes
+	Patch string `json:"patch,omitempty"`
 }
diff --git a/services/convert/convert.go b/services/convert/convert.go
index 0de38221409bb..ea371aff8b7e5 100644
--- a/services/convert/convert.go
+++ b/services/convert/convert.go
@@ -812,6 +812,7 @@ func ToChangedFile(f *gitdiff.DiffFile, repo *repo_model.Repository, commit stri
 		HTMLURL:          fmt.Sprint(repo.HTMLURL(), "/src/commit/", commit, "/", util.PathEscapeSegments(f.GetDiffFileName())),
 		ContentsURL:      fmt.Sprint(repo.APIURL(), "/contents/", util.PathEscapeSegments(f.GetDiffFileName()), "?ref=", commit),
 		RawURL:           fmt.Sprint(repo.HTMLURL(), "/raw/commit/", commit, "/", util.PathEscapeSegments(f.GetDiffFileName())),
+		Patch:            gitdiff.RenderUnifiedDiff(f),
 	}
 
 	return file
diff --git a/services/gitdiff/gitdiff.go b/services/gitdiff/gitdiff.go
index db0f565b526a0..fd8fbd23caf00 100644
--- a/services/gitdiff/gitdiff.go
+++ b/services/gitdiff/gitdiff.go
@@ -1058,6 +1058,88 @@ func createDiffFile(line string) *DiffFile {
 	return curFile
 }
 
+func RenderUnifiedDiff(file *DiffFile) string {
+	var sb strings.Builder
+
+	oldPath := file.OldName
+	if oldPath == "" {
+		oldPath = file.Name
+	}
+	newPath := file.Name
+
+	// File header
+	fmt.Fprintf(&sb, "diff --git a/%s b/%s\n", oldPath, newPath)
+	fmt.Fprintf(&sb, "--- a/%s\n", oldPath)
+	fmt.Fprintf(&sb, "+++ b/%s\n", newPath)
+
+	if file.IsBin {
+		return ("Binary files differ\n\n")
+	}
+
+	for _, section := range file.Sections {
+		// Compute hunk header
+		leftStart, leftCount := hunkRange(section, true)
+		rightStart, rightCount := hunkRange(section, false)
+		fmt.Fprintf(&sb, "@@ -%d,%d +%d,%d @@\n", leftStart, leftCount, rightStart, rightCount)
+
+		for _, line := range section.Lines {
+			prefix := " "
+			switch line.Type {
+			case DiffLineAdd:
+				prefix = "+"
+			case DiffLineDel:
+				prefix = "-"
+			}
+			sb.WriteString(prefix + line.Content)
+			if !strings.HasSuffix(line.Content, "\n") {
+				sb.WriteString("\n")
+			}
+		}
+	}
+	sb.WriteString("\n")
+
+	return sb.String()
+}
+
+// hunkRange calculates the start and length for either old or new file in a section
+func hunkRange(section *DiffSection, left bool) (start, count int) {
+	lines := section.Lines
+	if len(lines) == 0 {
+		return 0, 0
+	}
+
+	if left {
+		for _, l := range lines {
+			if l.LeftIdx > 0 {
+				start = l.LeftIdx
+				break
+			}
+		}
+		for _, l := range lines {
+			if l.LeftIdx > 0 {
+				count++
+			}
+		}
+	} else {
+		for _, l := range lines {
+			if l.RightIdx > 0 {
+				start = l.RightIdx
+				break
+			}
+		}
+		for _, l := range lines {
+			if l.RightIdx > 0 {
+				count++
+			}
+		}
+	}
+
+	if count == 0 {
+		count = 1
+	}
+	return start, count
+}
+
 func readFileName(rd *strings.Reader) (string, bool) {
 	ambiguity := false
 	var name string
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 325f0b78a0564..221cccd31ba03 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -22121,6 +22121,11 @@
           "type": "string",
           "x-go-name": "HTMLURL"
         },
+        "patch": {
+          "description": "The patch text for the file changes",
+          "type": "string",
+          "x-go-name": "Patch"
+        },
         "previous_filename": {
           "description": "The previous filename if the file was renamed",
           "type": "string",
diff --git a/tests/integration/api_pull_test.go b/tests/integration/api_pull_test.go
index 8376fd2717d3b..bc4c9497a4009 100644
--- a/tests/integration/api_pull_test.go
+++ b/tests/integration/api_pull_test.go
@@ -80,6 +80,7 @@ func TestAPIViewPulls(t *testing.T) {
 					assert.Equal(t, 1, files[0].Changes)
 					assert.Equal(t, 0, files[0].Deletions)
 					assert.Equal(t, "added", files[0].Status)
+					assert.Equal(t, gitdiff.RenderUnifiedDiff(patch.Files[0]), files[0].Patch)
 				}
 			}))
 	}